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More FAQs about Plumbing Closed-Loop Return Manifold Plumbing Issues

Related Articles: Plumbing Return Manifolds, Plumbing Marine Systems, Refugiums

Related FAQs: Closed Loop Recirculation 1, Closed Loop Recirculation 2, Closed Loop Recirculation 3, FAQs on: Rationale, Designs, Pumps, Troubleshooting/Repair, &  Marine Plumbing 1, Marine Plumbing 2, Marine Plumbing 3Marine Plumbing 4, Marine Plumbing 5, Marine Plumbing 6, Plumbing 7, Plumbing 8, Plumbing 9, Plumbing 11, Plumbing 12, Plumbing 13, Plumbing 14, Plumbing 15Plumbing 16, Plumbing 17, Plumbing 18, Make Up Water Systems, Pumps, Plumbing, Circulation, Sumps, RefugiumsMarine Circulation 2, Gear Selection for Circulation, Pump ProblemsFish-Only Marine Set-ups, Fish-Only Marine Systems 2, FOWLR/Fish and Invertebrate Systems, Reef Systems, Coldwater Systems, Small Systems, Large SystemsWater ChangesSurge Devices


Closed loop... pb issue; cavitation from too large pump, too small pb     8/11/14
I have a closed loop on a drilled tank, bottom has 5 inch bulk heads, i drain
<Wish there were two>
and 4 returns, i have a Iwaki rated at 1900 gph , 1inch in/out. Out is plumbed to pvc manifold that has flex to the 4 returns. I also have union valves on inlet and outlet.
When i try and run wide open it cavitates and produces lots of bubbles, if i back down it is fine. Question , would increasing the pipe size on the inlet to 1.5 inches help?
<On the intake side; yes>
It would still have a 1inch bulkhead and pump inlet ( just between a larger pipe)
<... need to re-drill the tank... Enlarge the bulkhead as well. Bob Fenner>
re: Closed loop
<What I'd really do is to change the pump on your current arrangement to something smaller flow-wise (like by half), and instead provide circulation within the system... via pumps, even powerheads... See WWM. Closed loops are for the most part passé nowayears... for a few good reasons. BobF>
Re: Closed loop     8/13/14

If I back it off I do not get bubbles , I do have some streams in side tank Thx
<No sense spending the money on electricity to throttle-back, nor the added waste heat of a too-large pump. B>

Closed loop system w/ chiller, pump, pb  7/3/12
First off hello and thanks for the great information you guys post on here.
Has been really, really helpful.
<Hello Dwayne>
I've got a 125g saltwater tank that I've had up  and running for 10 months now. I don't have much in it but here's the list. Two  ocellaris clowns (who are breeding and laying eggs consistently every few  weeks), one banded moray eel, about 150 lbs of live rock, 120 lbs of live sand,  medium size frogspawn, two small hammer coral heads, two bunches of candy  cane coral (about 8 heads each now), medium bunch (softball size) of green star  polyps, growing colony of a few hairy mushrooms and purple mushrooms, 3  white-tip hermits, and 30-40 Nassarius snails. I'm running a dual 400w Hamilton  metal halide, 55g sump with two Eheim return pumps (not sure on size but takes  two to keep up with overflow box), and two Hydor Koralia 1400 powerheads. I  seem to have pretty good movement in the tank but kept getting a lot of  temperature shifts due to the weather. I ended up buying a Arctica dba 150  chiller (which is now keeping the temperature pretty steady between 79-80  degrees) and have decided to hook it up in a closed loop system. I've run  all the plumbing with 1" pvc and am using a BlueLine Velocity T4 pump. I'm  pulling straight from the DT and pumping back into it on
this setup. The chiller  is rated to handle 480gph to 1320 gph, hence the reason to use the T4 (1275  gph). I'm not seeing the amount of flow from the two outlets in the tank (one at  each end for added water movement) that I was hoping to with the pump.
<From what I have read, the T3 and T4 pumps are identical in physical dimensions except that the T4 has a slightly larger impeller and one inch fittings.  I did not see anywhere where the T4 pumped more than the T3's 850gph.
Regardless of the gph, these measurements are at the head of the pump.  Any restrictions (elbows, valves, etc) and length of pipe will drop the gph rating significantly.>
I did  plumb in a cut-off valve to the chiller and when I bypass it, it does seem to  increase a little but not by much.
I'm also running the 3iQ Ventures SCWD (was  free) which seems to be working ( just slowly alternating due to low  pressure I assume).
<If this is ran by the Blue Line pump, you will see a drop in water flow. 
The SCWD uses some of the water energy to drive the unit.>
The pump is on the floor (58" to top of tank) and was  wondering if this could cause a big loss of pressure?
<Yes, any increase in the head will cause a loss.  It's always best to get more pump than you think you need and just throttle the pump down for your application.>
Could I go to a  bigger pump without hurting the chiller or would I be better running the  chiller separate?
<By what you state, I'm assuming you are not close to exceeding the maximum flow into the chiller.  You won't cause any damage to the chiller by pumping more water than the rating, you will just reduce it's efficiency by decreasing the contact time with the water.  For starters, I'd replace those 90 degree hose barbs on the chiller with straight hose adaptors. 
That alone will give you an increase in flow.>
 Thanks in advance for the help
and I've attached a couple  pictures.
<You're welcome.  James (Salty Dog)>
Dwayne DeLuca

Closed-LoopA Better Way to Strain? 02/23/10
Bob, Anthony, Andrew, et al,
<<Greetings strangerEricR here today>>
Hope you are all well,
<<Speaking for myself, doing fine thanks>>
has been a long time since my last communication.
<<Indeedconsidering its been about four years since Anthony left our team>>
I have set up several closed-loops in my day and have learned two valuable lessons; one of which I want to bounce off of the team.
For those starting a closed-loop system, wherever possible, utilize two drains to avoid noise and air, as well as controlling the flow 'more better'.
<<Ah yes, good advice Whether for this purpose or to drain to a sump, providing an adequate number of properly sized drain lines goes far toward alleviating such problems>>
Secondly, I have yet to figure out how to keep small debris/detritus/particulates from entering the 'loop'.
It drives me mad :). Esthetically, big ole' sponge filters on the drain intakes is just not going to work;
<<Agreedand would also clog/trap detritus/depress flow quite readily>>
but even the smallest sliver of an opening and voila, all my copepods are now in my loop, churned into mush by the impeller.
<<An overrated issue in my opinion. The bulk of the population will avoid thisand even those caught and churned into mush still provide food/benefit to the system>>
Not to mention that it surely would be nice to test/check/clean the loop pump only a couple of times a year.
<<This should still be the case>>
As a test, I did create 2 additional overflow areas just for the drains and used simple filter media over the pipe. This was not ideal but worked
<<Mmmbut adding unnecessarily to the maintenance of the systemagain, in my opinion>>
- I am an advocate of having the closed-loop pulling from lower in the tank, for 'stirring' things up.
However, the draw, after testing, did in fact detract from the primary overflow drain skimming a good portion of the proteins from the surface and popping them back into the water column, shaken and not stirred - primarily since the closed-loop flow is typically several times the filtration flow.
<<I seeso now a matter of gauging the benefit of one over the other>>
The issue is especially problematic on smaller tanks where a closed-loop would be ideal visually but no way to keep the drains or pump free of icky stuff.
<<Maybe sobut is a facet of marine plumbing>>
Are we all going to just buy Vortechs?
<<Hee-hee! Not meto dang expensive for a flow pump you cant even aim! I am a fan of Tunze Stream pumps thoughand prefer these to a closed-loop on larger home tanks as the pumps big enough for a closed-loop are almost always too noisy for use in living areas. And even on small to medium sized tanks, I think the Algae Free Sure Flow upgrade for the Maxi-Jet pumps is a great solution>>
Is there really such a thing as Blue Pom Pom Xenia if you don't use black lights or lots of blue lighting?
<<Mmm, yes I ordered some really blue Acros (based on the photos offered) off the NET a couple weeks agoyoud think after all these years I would learn>>
Am I eating too many M&M's?
Surely I am not alone in this?
<<Who you callin Shirley>>
Any thoughts?
<<Ideally you want to maximize the flow from your closed-loop pump. Aside from a plastic bulkhead strainer to keep your fishes/larger macro organisms from being sucked in to the loopI wouldnt worry about or try to restrict it any further>>
<<Happy to share! Eric Russell>>

Re: Question re. plumbing a closed loop manifold, pump pb  12/12/09
Thanks Scott for your quick response. One clarification, and subsequent question. It is in fact the Barracuda I am considering, but I got the G/hr wrong in my original e-mail. With an estimated 10 feet of head and at least 8 manifold openings at 350 G/hr per opening, I figure this kind of power is necessary.
<Will work fine.>
Anyway, these pumps come with a 1 ½ inch intake instead of the 2 inch that comes with the Dart. In your comments below, did you recommend going to a 2 inch intake instead of the 1 ½ inch because of the 2 inch intake on the Dart? Or is it a good idea to go with a 2 inch even though I will need to reduce it to a 1 ½ inch anyway before it joins the pump.
<I would intake with a 2" line at this flow, just reduce it at the pump connection.>
In terms of my options, I think I'll try the over the tank one first, but move to drilling a new hole if it doesn't work out as well as I would like. I will, however, start to read with more interest the FAQ's re. tank draining/relocation. Regardless, option 2 is off the table.
Thanks again. Andrew
<Welcome, have fun, Scott V.>
Question re. plumbing a closed loop manifold
Ah, knew I should have waited. One additional quick question. If I stick with the 1 ½ inch PVC vs. the 2 inch, but put one such "U" on either end of the tank and join them before it gets to the pump, will this sufficiently increase the flow capacity?
<In a similar way to using 2", yes. The 2" vs 1.5 is not life or death here though. The 2 is just "better", but the difference in flow will likely not even be noticeable to be honest.>
If I did that, would it be better that each "U" is separate or can they be at opposite ends of a common piece of PVC that spans the bottom of the tank?
<May be the way to go. I am a fan of multiple intakes when possible. Stuff always has a way of clogging up junk when you just have one!>
Let me know if I am not describing this well enough, and I will try my hand at PowerPoint again.
Thanks muchly. Andrew
<Welcome, Scott V.>

Re: Question re. plumbing a closed loop manifold, pump pb  12/12/09
Thanks Scott for your quick response. One clarification, and subsequent question. It is in fact the Barracuda I am considering, but I got the G/hr wrong in my original e-mail. With an estimated 10 feet of head and at least 8 manifold openings at 350 G/hr per opening, I figure this kind of power is necessary.
<Will work fine.>
Anyway, these pumps come with a 1 ½ inch intake instead of the 2 inch that comes with the Dart. In your comments below, did you recommend going to a 2 inch intake instead of the 1 ½ inch because of the 2 inch intake on the Dart? Or is it a good idea to go with a 2 inch even though I will need to reduce it to a 1 ½ inch anyway before it joins the pump.
<I would intake with a 2" line at this flow, just reduce it at the pump connection.>
In terms of my options, I think I'll try the over the tank one first, but move to drilling a new hole if it doesn't work out as well as I would like. I will, however, start to read with more interest the FAQ's re. tank draining/relocation. Regardless, option 2 is off the table.
Thanks again. Andrew
<Welcome, have fun, Scott V.>
Question re. plumbing a closed loop manifold
Ah, knew I should have waited. One additional quick question. If I stick with the 1 ½ inch PVC vs. the 2 inch, but put one such "U" on either end of the tank and join them before it gets to the pump, will this sufficiently increase the flow capacity?
<In a similar way to using 2", yes. The 2" vs 1.5 is not life or death here though. The 2 is just "better", but the difference in flow will likely not even be noticeable to be honest.>
If I did that, would it be better that each "U" is separate or can they be at opposite ends of a common piece of PVC that spans the bottom of the tank?
<May be the way to go. I am a fan of multiple intakes when possible. Stuff always has a way of clogging up junk when you just have one!>
Let me know if I am not describing this well enough, and I will try my hand at PowerPoint again.
Thanks muchly. Andrew
<Welcome, Scott V.>

Manifold Question 10-15-2009
I have a 180 that I want to use the manifold style return with the rectangular PVC going the inner rim of the tank with various T's for Loc-Line nozzles and I was wondering what size plumbing would you recommend? Right now I am going to use a Reeflo Hammerhead (It was a good deal and have it laying around) and was going to use the 1 1/2" to supply up the back of the tank to a 3/4" PVC rectangle.. Do you think the 3/4" is
too small, should I do 1"?
<I would stick with the initial 1.5", and plump the manifold so that it sits on the outside rim of the aquarium, but can be hidden inside the canopy. The hammerhead moves a LOT of water, and I'd be hesitant to reduce
the manifold to 1", much less .75"! However, a 1.5" manifold with ~ 10-14 .75" outlets should work great. Good to hear someone still plumbs/uses manifolds...I still don't understand why pumps like the Koralias are so "in", when a closed-loop manifold is infinitely superior...>
Thanks in advance,
<Mike Maddox>

Closed Loop Plumbing 2/4/09 Hello To all of the people who have inspired me to become a better fish keeper and now I am in the midst of a complete overhaul of my tank. <Great to hear, hello!> Onwards and upwards to the question at hand. I'm currently trying to plumb a closed loop using 2 pumps (what I have on hand) what would be the best route "t" together at the sump or can I have separate inputs on the closed loop? <Either can be done. You will just want to make sure the line is large enough as to not restrict the flow too much. What size pumps are we talking about?> I'm lost and would appreciate any input you would have. Robert McGee <Do also distinguish between a closed loop and sump returns. If these are feeding from you sump you will want to take a look at the overflows to be sure you have enough capacity there. Scott V.>

Closed Loop information, Return Manifold from Sump 12/31/08 Team, Happy Holidays and New Year. <Thank you and right back at!> Have not written in a while and hope everyone is well. <Tis here.> I have read several very good threads but would like input if you would be so kind. I inherited a 75g AGA standard system with a single 600gph, off center left MegaFlow. Nice tank, not very excited about the circulation possibilities. I am not a novice to CLS but not a master either. Bottom line, the tank is older, have checked with All Glass and the bottom and back appears to be tempered (also used the cheap polarized sun glass method :) ). <Surprising to me, glad you checked!> My favorite CLS option sans many powerheads is as follows (and I so love the remarks you all do in parens after comments :). Tear it up! <OK!> Intake: Utilizing the sump only, with check valve, unions for maintenance and ball valve some control in case of installing a larger pump. <Well, one issue already, the check valve. I know many will disagree with this stand, but they are completely worthless in marine aquaria IMO. The reason being they cannot be counted on to work, an little obstruction will keep the valve open.> Pump: More than likely a 1000-ish GPH like an Eheim MS or Quiet One 4000HH. Return: Four, 2 per side, slightly varied depth but no more than 4" down with loc line. Each side fed by a 3/4" SCWD. My plan is to then use loc line for positioning. On the end of each loc line feed, I will install 3/4" eductors to enhance flow while not overpowering the overflow. I also am toying with the idea of installing small ball valves on each individual run if I can get them to mount properly in an accessible fashion; I have plumbed myself in trouble several times - its no good to plan ahead when you can't reach things easily. <Agreed.> Basically, I am hoping with the eductors to augment the return flow so your opinion on the presumed flows is appreciated. <Sure.> - Example, a 980gph HH pump that has an initial rise of 4' would make the output roughly 850gph (it will be nearly a straight shot up actually less than 4'. - Installation of SCWD at the same height as CLS (basically) to reduce to 700gph appx. Each side of the SCWD having an outflow of appx 700gph, then factoring in roughly 1% loss per each linear foot of PVC (roughly 5'), overestimating 5% loss per right angle (max of 4) would equate to a 25% loss of pressure (and I think that's overestimating) leaving appx. 525gph. <A reasonable estimation.> If I can tune the two outputs on each side to effectively reach around 200gph, then adding a factor of 3 for the eductor, that would be a total side to side flow of 1200gph on each SCWD switch while still only draining 400 gph in the Megaflow (which should be about right for a Berlin or pseudo refugium so nutrients can actually process versus passing the bacteria by like fast food :) ). <But more than the 1 can truly handle. I do assume you will be using the ¾ throughput as a drain also, so you can handle the flow. But this does leave you with no margin for error/safety in the overflow system.> And yes, will be tapping the returns on the loc line branch about 1" below Megaflow teeth in case of check valve issue - large sump can handle an additional 10g or so on top of normal capacity. <Better to rely purely on sump capacity as you mention. Skip the check valve, if you have sufficient room in your sump there is no need for them at all, they only diminish flow from your pump.> Am I succumbing to wishful thinking or are my assumptions reasonable? I value your thoughts. <I will take another possibly unpopular stand re the eductors. These merely take a flow, pinch it down to a higher velocity and then force this high velocity flow into mixing with the surrounding water. This does cause more water to move directly out of the fitting, but I think it is misleading to consumers to say it triples the flow. It does, depending on perspective. Really for the amount of flow you will be able run through the overflow you will only want a single ¾ return or dual ½ returns. Four ¾ outputs here will give you next to no velocity out of each line to play with, direct your flow. If you want to keep away from powerheads you will need to employ a true closed loop (not from the sump), with an over the top intake much like those used by canister filters.> Take good care! Happy New Year! <Welcome, good New Year to you too! Scott V.>

Re: Closed Loop information, Return Manifold from Sump 12/31/08 Scott, Awesome, thanks. <Pleasure to help out.> A couple of things. Check valves, I hear ya, never used them, I will consider your comments. MegaFlow throughput is supposed to be 600gph. I am not quite sure, guess I will have to measure it with a flow meter perhaps <Yeah, 600 gph is the spiel, 300 is the reality.> Actually an over the wall CLS is not out of the question, however after reading several of the threads, even some of the WWW staff don't like it or didn't seem to. <They are not choice #1. They do require priming at the get go and anytime air is introduced into the line. Put it lower in the tank and you should only have to prime it the first time unless you drain the tank for some reason.> If I were to do it, for space between cabinet and tank, it would have to be max of 3/4". <May need multiple intakes depending on the flow you end up with.> I would even considering calling Paul in Canada at Oceans Motions and getting a 4 way Squirt and using something like a Reeflo or similar low wattage 1200-1500gph pump. <A nice way to go.> Or just 2 SCWD one on each side. Interesting, that way i could make the return more of a spray bar / surface agitator / back of tank circulation system. Very similar to drilled closed loops I have seen. My only worry is in the intake - what is the best recommendation for not having critters or gunk captured in the piping intake? <Just a simple PVC screen.> The benefit of having it from the sump return is that the water is pretty much polished before it gets to the pump. I would imagine similar to slip screen plumbing but I would probably do one intake on each side of the overflow in gray PVC as to minimize sight and have less chance of clog or mishap. I am a bit worried about how to secure the piping runs - with a tight canopy and no ledge... super Velcro? <I actually use the little peel and stick zip tie mounts found at the hardware stores. The things stick like crazy to just about anything. Just stick it and then zip tie your plumbing in place.> Anyway, the only drawback really is external pump space and any minor leaking - I guess I could use a couple of high powered submersibles also and plop in the sump. <One reason to go with submersibles, but with proper plumbing it really is not a concern.> Perhaps even some of that nifty flex PVC. <Good stuff, can be a lifesaver.> I also had not considered until just this moment the impact from dual 250w halides about 9" from the PVC - wonder if that will impact heat :). <Will be fine.> HNY Bill <Happy New Year to you too! Have fun, Scott V.>

Plumbing, Sump/Closed loop 9/18/08 Hello <Keith> Thank you all for this invaluable resource. I have just finished moving and built the stand for my tanks. I have a 150 oceanic AGA with dual 1.5 overflows sitting above a 180g AGA with a single 1.5 overflow. I am planning on the top tank being my display reef tank and the 180 on the bottom will be a refugium. <Wow, nice!> Since the 180 only has a single overflow I was planning on having one of the overflows from the display run straight into the fuge then the other lead directly into the sump skimmer chamber. The refuge would drain to the sump and join the skimmed water to be pumped back into the display. <This sounds good.> My question is I dont think that the 1 returns on the display will create enough water movement but I would already have to tee the return to get to both sides of the tank would I be able to plumb in a closed loop manifold with this system? <You could certainly plumb a return manifold, a Calfo article discussing exactly this: http://www.wetwebmedia.com/pbh2oret.htm.> What pump would you suggest for the set up I have and do you see any problems with it? <You will likely want an external for this, something comparable to the Iwaki MD30rlxt. A few things to note however. I usually do not encourage people to run too much flow through the sump merely due to the difficultly managing the flow in the sump. With a 180 gal sump this will not be an issue. If you do want to run all the flow you may need (depends on what you want to keep) through the sump, you will want to drill for a few more bulkheads, likely 2. Your two 1.5 bulkheads get you a safe 1500 gph, but that leaves no redundancy. Personally I would not run more than 700 gph through the existing throughputs, this leaves a 100% margin for safety. If you dont wish to drill you can run a true closed loop (water from the tank to a pump back to the tank) or throw in a few powerheads to supplement the flow.> Keith Fontes <Scott V.>  

New Tank Flow ProblemPowering The Return Manifold 04/05/08 Dear WWM Crew, <<Morning, Scott>> I am setting up a new 90 gallon reef tank and installed a Calfo Manifold, which I think will work great. <<If configured correctly, yesI would agree>> I love the clean design of the manifold. <<Me toosolves the issues of powerheads in the display. Although its not suited to every application (e.g. some living-area installations where a big/powerful pump might be too noisy)>> The problem is I am using an Eheim 1262 pump as the return and am getting pretty weak flow out of the manifold. <<Mmm, yes These are wonderful pumps (and wonderfully quiet!), but after headloss I imagine you have little more flow than that need to power no more than a couple ½ nozzles effectively>> Obviously, the pump is too small. <<Agreedand would help me greatly to know the size and number of output nozzles on your manifold. A good general rule-of-thumb is to allow 350+gph for each ½ nozzle, or 650+gph for each ¾ nozzle>> I'm considering switching to a larger Mag-Drive, but I saw comment in a FAQ about using 2 return pumps. <<Hmmplumbed in what manner, I wonder?>> I could add a second Eheim to the sump, but am not sure how to approach the plumbing into the manifold. <<Plumbing the pumps in series might be the best configuration to reduce the likelihood of working the pumps against each other, though I think you will still lose some efficiency. I think you would be better off simply acquiring a larger pump suited to your needs/the requirements of the return manifold>> This is the point where I could use some expert advice from the Crew. <<My advice is use one pump of sufficient size, based on the guidelines for flow I have provided>> Should I just go to the larger Mag-Drive, or add a second Eheim to the mix and plumb it into the same return line as the other Eheim? <<The first option>> How many GPH do you recommend to get adequate flow from the manifold so I can be forever free of power heads? <<As I indicated above, you need to provide more info for me to make a recommendation here>> This being a new tank, I really want to get it right before starting to add stock. Thanks much for your help, Scott <<Happy to assist, Scottand do write back with the specs of your project for further discussion if you wish. EricR>>

Re: New Tank Flow Problem...Powering The Return Manifold - 04/06/08 Thanks much, Eric. <<Welcome, Scott>> I have 4-1/2" nozzles fitted with Loc-line fittings with valves to adjust the flow as needed. <<Ah, okaythen you need a pump that will provide at least 1400gph, after headloss. I recommend getting something in the 2400gph range and installing a gate-valve on the output side to adjust flow if needed. Better to go bigger than you need and temper the flow than to go too small. Besides, you will be glad to have the extra power once the plumbing lines coat with organic matteryou can simply increase flow with the valve to compensate>> The output from the pump is 3/4" feeding into 1/2" line for the manifold. I am also bleeding off some of the main pump flow into a refugium. <<Mmmall the more reason for a larger pump>> I'm thinking to pursue a Mag-Drive 18 pump, which produces 1,375 GPH at 4' head (according to the manufacturer). <<Too smallI think you will be disappointed in the performance of the manifold with this pump>> I think the Mag-Drive 24 might be overkill, but I would hate to under-buy AGAIN! <<Indeed>> I also have to be careful of overwhelming the overflow (single 1 1/2" drain). <<Ah wellthis is your limiting factor. The single 1.5 drain means your flow is restricted to a mere 700gphnot nearly enough to power the return manifold. To make this work, you will need to plumb the manifold as a closed-loop rather than an open-loop through the sump>> I also looked at the Ocean Runner 6500 (1700 GPH) based on some posts in FAQ's. I'm not as familiar with these pumps. <<A very good brand of pump, in my opinionand preferred over the Mag-Drive but for the size limitation>> Of the two, what would be your preference? <<As statedyou will need to go with the larger Mag-Drive, and plumb the manifold as a closed-loop>> Thanks, Scott <<Happy to helpif you have more questions re the closed-loop, you know where to find me. Eric Russell>>

Plumbing A Closed-Loop Manifold In A 90 Gallon Acrylic Show Tank 01/28/08 Hello Crew, <<Howdy Mark!>> I need some suggestions regarding the installation of a closed-loop manifold. <<Okay>> Have read for hours looking for a similar question but didn't find one. I have a 90 gal acrylic show tank with a center overflow. The tank is not set up yet and is going to be totally enclosed in custom cabinets (like an entertainment center) with a flipper door in front for access to the top of the tank. <<I seesounds nice>> I'm going to drill the back several inches below the water line for a 1.5" bulkhead w/suction strainer to feed a MAG 18. I'm using a 1.5" bulkhead instead of 1" in case I want more flow later, but will reduce the size to 1" for the inlet of the MAG 18. <<Sounds fine>> I plan on using the existing predrilled .75 bulkhead to return water from the MAG 18 back through the overflow into my closed-loop. <<I think you will likely find this will reduce the output of this pump somewhat>> I want to connect the closed-loop with the return line via a short section of flexible clear tubing since the manifold will sit higher in the tank than the return hole in the front of the overflow. <<Understoodbut do consider using something opaque rather than clear, so algae will be less likely to accumulate in the line>> I have 6, half-inch lock-line nozzles to use in the manifold, connected to .75" PVC pipe. <<Too many You need to figure at least 350 gph per ½ nozzle to get any kind of useful flow. Even with no headloss, this pump comes up shy on the flow rate for this many nozzles>> The problem I have is with the "show" tank. There are only two openings in the top of the tank in which to get my loop into the tank. I will not be able to pre-build/glue the PVC manifold outside the tank and then place it inside. It simply would not fit through either opening. I don't like the idea of having to glue the PVC while it's inside the tank, to risky. <<Mmm, yesgood chance for marring the acrylic>> I don't want to spill/splatter/drip solvent on the acrylic walls. <<Indeed>> My question is, how have others gotten around this? <<When I installed my in-wall 375g acrylic reef display tank I originally built and installed a closed-loop manifold for it (later removed once I figured out a pump large enough to power it was just too noisy for the location). The way I got around the restrictiveness of the acrylic design (wide aprons/top bracing) was to lay the manifold atop the tank with the nozzles protruding down through holes drilled in the apron/bracing for this purpose>> I don't like the fact that if I put the manifold inside and glue it, I can't get it out of the tank without cutting it and I don't want to use unions because they would be visible. <<Agreedbest to keep the manifold on the outside of the tank>> I'm trying to keep the manifold out of sight as much as possible. <<Placing the manifold on top of the tank means only the nozzles will be visible within>> My other question is how to support the plumbing in a tank without a plastic lip running around it as with a glass tank. I'm not really keen on drilling holes in the top to install zip ties. I had a thought of making some acrylic brackets to glue inside the top, but had the same concerns about dripping, splattering, etc. Is there a more, less permanent, way to install a closed-loop in a tank like this? <<Yeswith the return manifold supported on top as explained>> Do you simply just not glue all of the joints? <<Noshould one come apart, think of the mess>> Another question. <<Okay>> I think I know the answer. <<Oh?>> Can I run my MAG 7 from the sump back into the same return line as the MAG 18, or should I drill another hole in the back of the tank to return the sump water separately. <<Best to keep these separateyou dont want these pumps fighting each othermaintenance of either also becomes more problematical/requires both systems to be down>> I'm cringing about drilling holes in a new tank! <<Understandableit also voids your warranty>> My gut tells me they need to be separated so the pumps don't fight each other. <<bingo>> The sump is fed from a 1.5" drain in the overflow. I'm drilling the stock 1" drain out to 1.5" per your suggestions and installing a stand pipe for noise reduction. <<Ah, excellent>> Thanks for a great resource, and thanks for all the great ideas! Mark <<Do let me know if you need more clarification re the return manifold atop the tank or anything else stated. Good luck with your project, Eric Russell>>

Re: Plumbing A Closed-Loop Manifold In A 90 Gallon Acrylic Show Tank - 01/31/08 Eric, <<Hello Mark>> Thanks for the ideas and input. <<Quite welcome>> I was calculating my 1/2" nozzles at 300gpm based on 1800gpm at the pump. <<I seebut this does not allow for headloss. I can only speculate without knowing the specifics of your whole plumbing design, but you can probably figure on losing at least a third of the pumps rated capacity due to friction and gravityall greatly related to the length and height of the runs. At best, this limits you to four ½ nozzles with the pump you have selected (MagDrive18)>> Have seen the range of 300-350 per outlet for this size posted. <<Indeedbut better to lean towards the high-side when possible>> I was on the low side...should probably drop back to 4 nozzles to get more velocity at the outlets <<Yesand even then, you will likely still be on the low-side>> ...was thinking that if I had more outlets around such a short tank (48x18x24) that sacrificing a little velocity for more outlets would generate more turbidity with the streams being aimed at/across each other. <<Just doesnt work that way Im afraidthe loss of flow/velocity of even one too many nozzles is tremendous. But You neednt just take my word for it. Install as many nozzles as you want or think you might need for a later pump upgrade and see how the loop performs with your current pumpyou can always cap nozzles as needed to obtain the necessary velocityand having extras will allow for future adjustments as the corals grow>> I like the idea of having the manifold around the top...had thought of that but also thought that it may be susceptible to salt creep and ruled it out. <<EVERYTHING is susceptible to salt-creep my friend [grin]. But it wont be all that bad, reallyand beats having the entire return manifold exposed within the tank>> To keep that from happening I guess you could use 1/2" bulkheads in four spots <<Hmm, a very interesting thought But one problem I see with this is how to attach the loop to the bulkheads. The nozzles could be friction-fit to the bulkheads on the inside of the tank, but the manifold atop the tank would need something more secure. You could solvent-weld the manifold in place but then it cant be easily removed/moved out of the way if/when needed. You could install unionsbut this would likely raise-up the manifold to the extent it becomes a pain to access the tank. If you truly want a seal around the nozzles where they extend through the top, look in to flex tank adapters, also called Uniseals. These come in various sizes to fit common PVC pipe diameters and are installed as a push fit. Once you install the Uniseal and insert the pipe you have a watertight seal>> .....but then again drilling the tank close to the edge isn't a good practice either. <<No need to get up next to the edgedrill the holes midway between the tank edge and the edge of the top perimeter brace and you should be fine>> So...I'll give....how'd you do it? <<I drilled through the top perimeter brace of the tank for each nozzlea little more than an inch in from the tank sides>> Pump literature says to use 1 1/2" plumbing at the outlet of the pump. Could reduce 1 1/2" into 1" around the top and then reduce to 1/2" at each outlet. Would be less loss at the pump...but seems a bit big? <<AgreedI would go ahead and use ¾ pipe for the manifold with the ½ nozzles, and size pump as necessary>> Was originally planning on 3/4" around the top and then 1/2" at outlets. <<Works for me!>> Thanks again, Mark <<A pleasure to share. Eric Russell>>

R2: Plumbing A Closed-Loop Manifold In A 90 Gallon Acrylic Show Tank - 01/31/08 Thanks Eric, <<Welcome Mark>> I'll look into the Uniseal concept. <<Good deal>> Did you just drill holes big enough for the outlet of a tee to pass through the top and leave it unsealed or did you fasten the plumbing to the hole somehow? <<Just the hole The weight of the manifold holds it in place quite well And splashing/salt creep was not much of an issue at all>> What would be cool is if you could get a 90 street ell with a bulkhead nut. You can get these for hydraulic apps to go through panels and such with hoses...not sure they do that for PVC....never seen it anyway <<Neither have I>> ...but then again I didn't know about the Uniseal either. <<Wonderful devices Some of the high-end skimmer manufacturers use these in their skimmer construction>> Maybe we could make them...business opportunity! <<Would think it would be a simple matter to cement the PVC street-ell to the nut>> What would really be neat is making a chamber in the top of the tank that provides a pre-fabricated manifold into the top piece prior to assembly to the walls. It would add a few inches of height to the tank but if you keep the overflows below it you'd never see it. <<An interesting idea/concept/design>> Would have to increase the height of the canopy to cover it...but thats easy. <<Indeed>> As far as losses go, there shouldn't be a tremendous amount of head loss...at least not like there is returning from a sump. With the suction side flooded from water near the top...the delta Z in old Bernoulli's equation isn't but a few inches from the suction side to the manifold height...i.e. the water is falling about as far as the pump has to return it. This loss should be negligible. All you're left with is a few feet of head from frictional losses maybe, 3 to 4' max the Mag 18 should do about 1300gpm which for 4 nozzles gives you 325gpm worst case. Sound logical? <<Mmm, yesand about as much as I would expect from this pump returning from a sump. Ill admit I dont have a good grasp of Bernoullis equation (What I have read seems to calculate the power of a pump/flow based on height, distance of fall, initial velocity, etc.), but the pump must still overcome gravity and mass to push the water back to the tank>> Should I just put the nozzles in all 4 corners? Mark <<This is how I would do itit will provide the most function/flexibility while being the least obtrusive configuration. EricR>>

Plumbing A Closed-Loop Manifold 01/15/08 Hi Crew, <<Hello Jim>> I've been reading Anthony's page about a closed-loop return manifold, and I am planning to build one. <<Neat... Can be quite useful>> I just had a couple quick questions after reading the article. <<Okay>> First: I have a Perfecto 150H "Reef Ready," which is woefully inadequate, as Anthony said. It had one overflow, with a 1.25 inch drain and a 1" return. <<Hmmbut still, better than those other reef-ready with 1 drains and ¾ returns that abound>> Warns to run no more than 600 GPH. <<Im impressedmost would state about double thisthough Im inclined to say something closer to 500gph would be prudent>> Well, I slightly widened the slots in the outer wall, and slightly lowered the top of the inner wall, and drilled another air hole in the elbow at the top of the drain, and I think I am draining closer to 700GPH, but that's maxed. <<Really? But at what cost (noise/bubbles)? Do perform a test to confirm to confirm (time the filling of a vessel of known volume)I would be interested in your findings>> Since I am planning a manifold return, and am setting up a DIY recirculating skimmer, which I would love to simply gravity feed, is there some particular reason why it would be a bad idea to cut the top off the return, maybe 1.5-2 inches below the opening on the main return, and use it as a bubble-free drain for the skimmer (with a valve)? <<You mean as in having the tank drain flow directly in to the skimmer? Nope, I dont think this is a bad idea at allassuming the skimmer is designed for such>> Second: I am planning a complete loop around the top of the tank, as suggested. I was planning to include 9 tees--four across the back, one at each end, and three across the front. I was planning to use 1/2" PVC or even CPVC to extend two of the tees down behind the rockwork, where elbows could be used to direct some water around inside to clear out detritus. <<Mmm, I dont think this will work as desired. The resistance/backpressure from the water in the pipe extended below the waterline will render the flow all but useless at these two nozzles. If you wish to do this, the two submerged nozzles will need to be isolated from the rest of the loop and provided with their own pump>> I was going to use loc-line on the remaining seven, with flat flares on the rear two and round nozzles on the sides and front. Is there any reason not to do the "down behind the rockwork" thing? <<Only for the reason statedbut can surely be done as a separate closed-loop>> Is 7 nozzles too many? <<Seven nozzles are finethough the efficacy of this closed-loop will depend on the size of the pump employed. ½ nozzles will require a pump capable of providing at least 350pgh per nozzle after headloss. ¾ nozzles will require at least 650gph per nozzle after headloss>> Would 1/2" loc-line be adequate, or would I need to use 3/4" (1/2" is so much cheaper, but I don't want to invest so much time and effort and go too cheap on the nozzles)? <<1/2 will be fine>> I am using a submersible pump rated for 1300 gallons, which I figure should be pumping 900-1000 gallons when I am done. <<Mmm, that means no more than about two ½ nozzles on the loop else flow will be feeble at best. To provide adequate flow volume to seven ½ nozzles, you will need to start with a pump in the 3000gph rangemaybe larger, depending on its power/susceptibility to headloss>> Thanks so much! Jim <<Happy to assist. EricR>> Re: Plumbing A Closed-Loop Manifold 01/15/08 Hi Eric, <<Hey Jim!>> I also like the idea of gravity feeding the skimmer directly off the tank; my specific question was: is there any reason it's not a good idea to chop the top off the "return" and use it as a drain? <<Ah! Sorry matedidnt get it the first time. And to answer your questionno reason at all not to do as you describe. Of course, Im sure you understand this means you will have to fashion some type of over the top return from the pump>> As for number of nozzles, ½ should have 350GPH each? <<Afraid soif you wish to have any kind of force/useful flow from the nozzles>> Because I was planning to run this manifold using the return off my sump, but I know there is no way I will get much over 1000GPH input, even using both bulkheads for drains, and I don't have any additional drains right now. <<Mmm, yesand do understand, a return manifold does NOT constitute a closed-loop when fed from an open sump return pump (the word closed is quite definitive here). This changes things greatly as you are no longer limited by the size of the return pump, but rather by the size/capacity of the drains leading to the sump. In your case, if you use both throughputs (1.25 & 1), you will be limited to something in the 800gph range after headlossmeaning two ½ nozzles on the manifold, at best>> I guess I could set this up as a separate closed loop, isolated from the sump return? <<To be a true closed-loop, yesand to get the flow you want, definitely>> How would I plumb the intake? <<Best done through the side/back of the tank. It can be placed as deep as you like, though you should keep access for maintenance/clearing blockages in mind before burying it at the base of the live rock>> The tank is already running, and I am too scared to drill it anyway (took three years of saving my pennies to get it). <<Pityis easier than many folks think (and only requires a partial drain of the tank)but I do understand your hesitation re>> An overflow (or several, more likely)? <<Theoretically, a feed to the closed-loop pump via a siphon overflow is possible (plumb the pump directly to the bottom of the external box), but finding one suitable for the typically high flow rates involved will be a challenge for sure. Perhaps a DIY rig spanning the length of the tank back and fed by a dozen or so 1 siphon tubes (number depending on pump flow rate) spread along that lengthbut, this would have the potential to be very unsightly from within the tankand probably a maintenance nightmare to keep all the tubes running>> Thanks again. <<Hope this proves helpfuldo let me know if you want to discuss other options. I will state that for tanks of this size and somewhat larger, requiring several to even a couple tens of thousands of gallons-per-hour water flownothing beats Tunze Stream pumps for high-flow efficiency, power savings, simplicity of installation, and quietness of operationin my humble opinion. Regards, Eric Russell>>

Closed-Loop questions 1/11/08 Crew, <Joe> I am currently in the process of setting up a 210 gallon AGA tank. I want to drill the tank for two different closed loop systems. The first will be a spray bar along the bottom of the tank that the live rock will be built up around. (was thinking that I will run this in 3/4" PVC with a flow of about 1500gph or so) <I would make it 1 pvc for this flow.> This will keep the rock from building up wastes. The second will be a system of Anthony Calfo's design around the top of the tank. (was thinking that I will run the manifold in 1" PVC with 1/2" nozzles, or should I go with 3/4" nozzles?) <Depends on the number of output desired. For 3500 gph I would go with five ¾ or eight to nine ½ outputs.> (If I go with 1/2" I am figuring about 10 nozzles for a flow of about 3500gph, 350 per nozzle) That said, my questions are these; can I run both loops off of the same pump? <Yes, with the amount of outputs a very large pump.> I would much rather purchase one pump than two since they are not cheap. I was thinking about running both loops off of a Sequence Hammerhead pump with ball valves on each loop so that I can adjust the flow Going to each. Will this work or would I be better with two separate pumps? <Two pumps has its advantages. If one pump fails you still have circulation while waiting for a replacement/repair. Consider running two Darts, or even a Dart and Snapper for this application, this will make intake plumbing easier also.> Where should I place my intakes? I would like to hide them but then again I don't want to tear my reef apart to clean them so I was thinking of just putting them about 3/4 of the way up the back of the tank. <I would be sure to place them in a position for easy cleaning.> What size should the intakes be and how many? The hammerhead has 1 1/2" threaded connections so I was thinking that I would have 4 intakes drilled in the back of the tank for 1 1/2" or even 2" bulkheads and tie them all together to feed the pump. <I would opt for two 2 intakes here. The same for the dual pumps.> This way the flow at any one intake is not enough to suck up any animals. So the back of my tank would like something like this, _______________________________________________ [ ] [ X X X X ] [ ] [ ] [ ] [ O ] [______________________________________________] In this simple diagram the Xs are my intakes and the O is my return for the spray bar (should I make the spray bar return an 1 1/2 bulkhead and then choke it down or should I choke down before the bulkhead?) <After the bulkhead.> The return for Anthonys loop will come up over the back of the tank. One other questions, I have not yet purchased the skimmer for this tank. I want a really powerful skimmer as this will be a almost entirely SPS tank, I was thinking of a ASM G-5 or a Lifereef VS3-36. What skimmer would you recommend for this tank? <I really like the ASM skimmers, I would also be considering a Euro-Reef as well.> Thanks for all your help. Joe <Welcome, good luck, Scott V.>

Spraybar/Closed-Loop Questions 01/08/07 Crew, <<Hiya Joe>> First I just want to say that the web site is fantastic. <<Were pleased you think so>> I have found it a great resource as I have been setting up my various tanks. I am currently in the process of moving up from a 90 gal reef to a 210 gal AGA Mega-Flow tank. <<Excellentand since you have been reading, I assume you know how many of us consider the Mega-flow moniker to be a misnomer>> The tank is going to be a mostly SPS dominated tank so I want to have two separate closed-loop systems in the tank. <<Okay>> One will be a spray bar system that the live rock will be placed around to keep waste from settling anywhere in the rock. My questions on this system are; where should I place my intake (could it be placed inside the Mega-Flow to hide it or would the Mega-Flow not be able to keep up?) and how large should the intake be? <<Dont place the intake for your closed-loop in the drain overflow boxthe box is not designed to handle the additional flow. Otherwise, you can position the intake anywhere you likethough low-down on the back/sides will likely be easiest to hide/disguise. As for sizematch the closed-loop intake to the size of the pump intake>> How large should the piping for the whole spray bar be (I was leaning toward 1")? <<For the spraybar itself I would think ¾ pipe would be sufficient, as well as less obtrusive. The pipe feeding/leading up to the spraybar should be at least as large as the pumps output nozzle>> How large will my pump need to be (I was think something around 3500gph)? <<Generally, the size of the pump for a closed-loop is determined by the number and size of the flow nozzlesbut a spraybar will not be so easy to calculate I think. Obviously the size and number of perforations in the pipe will ultimately determine the force of the flowand is quite easily adjusted for here as compared to a conventional loop. I think you can use about any size pump you like and experiment with the spraybar to achieve the best results re. But personally, I think 1200-1500 gph for the spraybar would be sufficientreserving the/a larger pump for your other closed-loop>> Should the spray bar be fed with one or two returns? <<Either way is fine, though a pair of returns to feed the pump offers some redundancy as well as a decrease in suction/danger to your livestock>> Lastly, is this system compatible with a deep sand bed (I feel like it should be as long as I lift it 5" or so off the bottom to allow for the sand and keep the holes pointed up)? <<Indeedas long as you take the flow direction in to consideration as you mention>> The second closed-loop system will be of Anthony Calfo's design along the top of the tank to provide random flow. <<Excellent>> My questions for this system are the same questions about intake (placement, size). <<And my answers are the same>> The same question about pump size? <<As stateddetermined by number and size of flow nozzles. You should figure (after headloss) about 350gph per ½ nozzle and about 650 gph per ¾ nozzle in order to achieve enough force to create a purposeful flow>> How many nozzles should be on the system (the tank is 6' x 2') <<I would employ at least sixeight if you have the pump for it>> What size should the piping and nozzles be (I was thinking 1" or 1 1/2" piping to 3/4" nozzles)? <<Again, match the feed pipe to the output nozzle of the pump (or slightly larger if you wish). The ¾ nozzles will be fine if a large enough pump is used, but on all but very large systems my preference is to use ½ nozzlesless intrusive, more forceful flow, can add more per a given pump size>> Do you think that this is a good setup for a SPS tank? <<Match your nozzles and pumps correctly and these closed-loops should serve well>> Please let me know if there is some way better for me to be doing this. Thanks so much for the help. Joe <<Happy to share. EricR>>

Drilling For A Closed-Loop...Use The Correct Bit Size 12/12/07 Hello, <<Hiya Steve>> I recently purchased a used 100 gallon long tank (60 x 20 x 20) and am in the planning stage. I would like to bring the tank to my local glass shop to have it drilled for the closed loop. (I really like the neat appearance of a tank with a drilled closed loop & no power heads or PVC to look at.) I will be using a Pan World 50PX-X external pump. I calculate around 775 gph after head loss. <<Hmm, with this flow rate you should only expect to use a couple ½ nozzles or a single ¾ nozzle for the return, and still have any useful force/strength to the flow. A good rule-of-thumb is to figure 350gph per ½ nozzle and 650gph per ¾ nozzle. Much less than this, and the water wont exit with enough force to have much effect>> (My return from the sump will be running through a Mag 9.5 and should turn around 570 gph after head loss.) I am planning to drill three holes in the back glass for 1 bulkheads. <<This size throughput should be fine for the closed-loop, but do consider 1 ½ bulkheads or larger for any gravity drain lines>> One will be an intake with an overflow strainer located dead center, about 1/3 of the way up from the bottom of the tank. (Should I use two intakes instead of one?) <<One throughput for the pump intake is fine, but to minimize effects from obstructions/blockages, consider using a wye-fitting and two bulkhead strainers to supply the intake>> The other two will be returns drilled 2/3 of the way up 15 from either side. Problem: My local glass shop only has a 2 drill bit and the manufacturer of my bulkheads suggests a 1 ¾ hole. <<Yes...this is the correct size for the fitting>> It seems to me that the 2 inch hole may work, but I would like a second opinion on this. I have successfully used a one inch bulkhead in a 2 hole on a 29 gallon tank, but this tank would be much more expensive to replace if a problem occurs. <<I dont recommend this, the 2 hole provides too much play/removes too much material behind the rim/lip of the bulkhead for a strong and secure seal. Best to use the correct size bit for the bulkhead. A correct bit can be purchased for around $50...perhaps you can offer to buy the bit and let the glass shop keep it for drilling the holes...>> I have also considered just drilling one hole for the intake and running the returns over the back, although this is not my first choice. <<This will work...though I like your first option better>> Thanks for taking the time to guide me. <<Hope it helps>> Your advice is greatly appreciated. Steve <<Happy to share. EricR>>

Re: Drilling For A Closed-Loop...Use The Correct Bit Size - 12/12/07 Thanks for the great help!!! <<Hope it proves worthy>> I took your advice and ordered the 1 3/4 inch bit. <<Ah, very good mate>> I do plan on using 1/2 inch nozzles on the two returns from the closed-loop. <<Is best>> Do you think that 775 gph (after head loss) will be sufficient? <<This will depend much on species kept, placement in the tank, aquascaping But coupled with the flow from your sump return it will likely be fine>> I don't want to add powerheads to the tank later. <<Understood>> (My inhabitants will be mostly softies that I will transfer from my 55 gallon. Here is a pic of my 55 http://i225.photobucket.com/albums/dd214/SFontana1/55-1.jpg.) <<Very nice, though if I may That Rose Anemone should be in a tank of its own And the Sun Coral colony will require direct feeding for long-term health>> The 100 gallon tank I purchased is reef ready. <<Yes, wella common misnomer>> It came with one corner overflow, containing a 1" drain and a 1/2" return. <<My case in point These throughputs are hardly adequate on their own for reef type flow, like the term reef ready would have you think. Consequently, these throughputs will limit the size return pump to something that will provide no more than 300gph after headloss>> If both bulkheads were one inch, I would make them both drains. Would it be worth it to convert the 1/2" bulkhead to a drain?? <<Only if you want to maximize the capacity rethough any increase will be very marginal with the addition of a ½ bulkhead drain>> I guess I could always drill another hole on the opposite side of the tank close to the water line for a second drain and use a strainer fitting. <<Ahhnow youre talking!>> What would you suggest? <<Another 1 ½ bulkhead to supplement the drain, as you describe>> Thanks for taking the time to help. Steve <<Always a pleasure. Eric Russell>>

Water return manifold question 10/31/07 After reading Anthony's article "Plumbing a Water Return Manifold - goodbye powerheads!" I decided to have a go at it. I found it to be rather loud, so I inserted PVC into the "T's" so that the water would flow into the tank below the water line. This solved the noise problem (along with the stand pipe I found out about here-thanks!). But my question is: without agitation at the surface, will there be enough o2? Even with the overflow box there seems to be no water movement on the surface. If I take out the PVC (so water comes into the tank above the surface) there seems to be enough movement... but then there's the noise again. If the pump is sufficient to turn over enough water per hour, should it matter if the surface of the water is smooth? <Hi Jen, you will lose some gas exchange with the calmer surface. It really shouldnt be a concern with adequate flow through your overflow and skimmer. If you wish to keep it quiet and agitate the surface you could put a 45 or 90 degree fitting on the end of one of the pipes and angle it a little towards the surface or get some Lockline which will allow you to easily put each output wherever you would like. Some actually advocate for a calm surface to increase skimmer performance (surface water being more concentrated through the overflow to the skimmer).> Thank you in advance for your answers and for providing a wealth of information here! Jen PS- yes, if a woman can plumb this manifold thing anyone can do it <Thank you very much. The two best reefers I know are women. Their tanks are the envy of all the locals here. If only my wife will plumb my next project...Scott V.> <Jen, I wanted to edit the spelling of the plumbing product I referred to, it is Loc-Line. Thanks, Scott V.>

Manifold Question...Flow Rate/Velocity vs. Nozzle Size 10/04/07 Crew, <<Hello...whoever you are>> Thank you in advance. <<Happy to help>> I am in the process of setting up a 240g. fish/reef set up. I have acquired the Dolphin AMP 4000/3000 for my return pump. It can pump more GPH using a 2" return line. <<Mmm yes, 4500gph...but starts to fall off quickly with head pressure/height (4000gph at only 2ft of head height)>> The tank is an acrylic with four equal sized cut outs on top to accommodate my four MH lights. I am planning on splitting the return line into two lines, then two off of each of those two, that will then terminate with one return at each of the four cut-outs. <<I see>> Should I reduce the four terminations to 1.5" or smaller or leave the whole manifold piped at 2"? <<I would at least reduce the terminations/nozzles. Lets figure with subsequent head-loss from the plumbing configuration that flow will be reduced to at least 3000gph en toto...maybe more. A ¾ nozzle requires about 700gph to produce a useful velocity for what you intend, so this is what I suggest you use (4ea. ¾ nozzles at 700gph = 2800gph minimum total flow required). If you find that your total water flow is reduced further than this then a ½ nozzle may be required...or switch to a pump with a better pressure rating>> Will 1.5" give more pressure to better reach the depths of the tank? <<Not at the terminal ends/as a nozzle size...as explained>> My concern is that if I leave all 4 outputs at 2" the GPH will remain the same but the water will simply be falling out of each return with not much pressure to agitate tank water. <<Exactly>> What do you think? <<You have my thoughts re>> Thanks! <<Quite welcome. EricR>>

Some General Questions On Sump/Closed-Loop Plumbing 07/03/07 Hi. <<Hello>> I was wondering if you could please answer a few quick questions regarding plumbing. <<Sureask away!>> I am setting up a 135-gallon reef with 55-gallon sump. <<Very nice>> Currently the tank has 4-holes drilled in the upper back glass panel that fit 1-inch bulkheads. <<Okay>> I'm planning on using all 4 as overflows out of the tank. <<Do figure only about 300gph perstill, 1200gph is a LOT of flow to process through the sump (if that is your plan)>> I was planning on plumbing 2 of the overflows down into the sump where an Iwaki rxt30 <<I think you mean the 30RLXT?>> (19 gallons/minute at 0 head) will return the water back into the tank (approximately 5-feet head). <<Be sure to plumb a gate-valve on the output side of the pump to allow tempering of the flow if necessary>> The other 2 overflows I planned on incorporating into a closed-loop system with another pump similar to the Iwaki with similar flow rate (I don't have it yet). <<Ah! Excellentbut you really only need one of these throughputs for this purpose>> Would the two 1-inch overflows per pump be sufficient to minimize sucking and gurgling noise, or should I plumb all 4 overflows down into the sump, forget about the closed-loop and use some powerheads instead? <<If you keep the flow rate for the sump drains in the range I suggested you will likely be fine, although even then sometimes a bit of tweaking (aspirating the lines, experimenting with different configurations of the termination ends, etc.) can be necessary due to the vagaries of system design. As for the closed-loop, a single throughput directly plumbed will be enough to supply the pump (the fluid dynamics are different than those associated with gravity drains). You could use the last bulkhead to supply the sump and be even further ahead of the gameor even use it to supply an in-line refugium>> Or even a third option: use 3 overflows for the sump and 1 for a closed-loop with a smaller pump? <<You can do this with you current planned pump. Unless there is something about your design that will restrict the water volume (e.g. bushing down the pipe size), as long as you match the bulkhead/pipe diameter to the intake port on the intended pump you should be fine>> What size (flow rate) pump would work ok with a 1-inch overflow to minimized gurgling and sucking noise? <<As explainedunless the throughputs are positioned very close to the surface where a very strong pump/flow rate may create some cavitation. But again, be sure to plumb a gate-valve on the output side of the pump>> Also, on the return plumbing from the sump (and closed-loop if there will be one) should I reduce the 1-inch return pipe just before it enters the tank after the T, or should the two pipes putting water into the tank remain 1-inch (the output on the pump is 1-inch)? <<Reducing the diameter as you indicate often makes the return easier to handle/place/disguise, but will also reduce flow/add to head pressureas will that T you mentioned. All the more reason to slightly oversize your pumps and adjust flow with the gate-valve if needed. For the closed-loop, to will need to reduce the terminal ends/nozzles to ½ to achieve a useable velocityand then likely no more than two of these (for closed-loop applications figure about 350 400 gph per ½ nozzle)>> Lastly, should the bulkheads be slip or thread on the outside of the tank portion? <<Is up to you>> I want thread so they can easily be removed just in case, but am worried about leaks. <<I wrap my threaded fittings with several layers of Teflon tapeor you could smear some silicone sealant on the threads just before assembly and let it cure before use (this doesnt glue the joint but does help greatly with creating a drip-proof seal>> Your expert opinion would be greatly appreciated here. <<Mmm, dont consider myself an expertbut prefer to think of myself as a student of the hobby>> Thank you Jon <<A pleasure to assist. EricR>> Closed Loop Filtration, SW "filtration"...    5/24/07 Hi Crew! <Ryan> I'm going to be building a FOWLR aquarium that has a requirement of four viewable sides. This means no overflows. <Mmmm... not really> I'm going to have to run the plumbing directly out and back in through the bottom of the tank. <See> I've seen this done using UV and Canister filters inline, however those two aren't my first choice of filtration. I would like to have a refugium on it, but I'm not sure how that can be done with a closed loop or with all of the plumbing coming out of the bottom. <Not with a "closed" plumbing arrangement... but one that is "open", sure. You can/could have both types... two separate sets of plumbing...> If a refugium is not a possibility, what are some other filtration mechanisms I could consider? <Heeeeee! Please read here: http://www.wetwebmedia.com/marsetupindex2.htm> Thanks! Ryan <Welcome! Bob Fenner>

Re: Closed Loop Filtration   5/24/07 Bob/Crew, Thank you so much for your reply!  I have three addendum questions. I realize I could send overflows up through the bottom of the aquarium to the place where I would want the water line, near the top of the tank.  However, this tank is going to be four feet tall. <Height doesn't matter... functionally... Are you concerned re appearance?>   (55"L x 24"W x 48"H) <Yikes... hard to aquascape and maintain...> So my questions are: 1)  In your esteemed opinion, <Steamed more like it> would glass be a better cost conscious option over 1.25" acrylic for a tank this tall? <Mmm, posted... I would go with acrylic myself...> 2)  Would you use an internal overflow for this setup to have better gaseous exchange/oxygen saturation? <Mmm, better than what? Likely not an issue here unless the power goes out or there is a pump failure...> 3)  What would be a good method to make a 3'10" overflow and return look "natural"? <A bunch of possibilities... one could attach phony corals, pile up real or faux rock about...> I'm thinking I could build  pvc structures like the one I have below (best I could do with clear text) and zip tie live rock around the pvc (not drilling through the pvc).  This would give it an arch like feel and I could hide the plumbing for the closed loop canister filtration in here as well. <Yep> Overflow on left, return on right.        |                     /       /|                    / \     /  |                   /    \   /    |                  /       \ /     |                 /         \    |      |                |           | Thanks again for your time and sharing of knowledge! Ryan <A pleasure to share... I would also like to add that if it were mine, I'd "sleeve this overflow... to "make" the discharge water come from near the bottom... have an outer pipe notched at the bottom, going over the internal stand pipe... this one could be drilled to accommodate the zip-ties... Bob Fenner>

Manifold Question. Siphon-Fed Closed-Loop 05/23/07 Hi: Joe here. <<Hello Joe...Eric here>> Thanks for all your valuable information. <<Quite welcome...is a collective effort>> I have a 90-gal tank that I would like to add a "closed-loop" system to. <<Okay>> Like many people out there a drilled tank is not an option. <<I see>> Anthonys remarks tell me he hates over-the-tank-lip systems to an external pump, lots of us have no option. <<Agreed and agreed...even if not for the best reasons in some cases>> Other members of the crew say it will work. <<Mmm, I think even Anthony will concede they work...for a time.  The inarguable truth about siphon overflow systems is they will fail sooner or later.  But, there are things we as aquarists can do to mitigate this hazard.  Obviously, daily (when possible) checks of the system to note a decrease/loss of siphon are critical.  But the truly wise hobbyist will also plan for/employ redundant systems (a concept Ive come to appreciate much more just lately).  Providing more than one pump input siphon will also reduce the amount of suction/pull at each intake, thus reducing the hazard to your fishes/motile inverts>> I plan on using a Mag 3400 with a 1" intake. <<Danner Supreme doesnt manufacture a 3400 model of the Mag-Drive pump, you must mean a 3600.  But that aside...pulling this much water through siphon overflows is going to prove interesting I think...please do let me know how things go>> The outlet will be 1" up to the tank, then to 3\4" manifold and 1\2" at the nozzles, 6 nozzles. <<Expect to need about 350gph per nozzle after head-loss, to get any kind of meaningful flow>> Is my plan ok? <<Mmm, maybe...though I dont think Ive ever seen this done this way before.  How do you plan to protect the intakes of the siphon tubes?  I dont think using a skimmer box is practical giving the amount of flow...perhaps it is best to simply install something like the screens used on bulkhead fittings>> I know over-the-tank-lip is not the best, but this is my only choice, isnt it? <<Cant say...you havent provided enough detail about your tank/setup.  If all the tank panels are tempered then yes, this is about the best you can do aside from going with internal mechanisms like the Tunze Stream pumps.  If the tank is not tempered then what is preventing you drilling the back panel?>> Some suggestion is putting the pump in the tank, but this pump draws 380 watts, and I thought heat could be a problem. <<Agreed...along with the trouble of trying to hide/service the pump in the tank>> Thanks again for all the great information. <<Happy to assist...and as stated, I would be interested to hear how this project turns out.  EricR>>

Return Manifold and Pump Size? - 03/03/07 Hello to all and thanks in advance, <<Howdyand youre welcome>> In an effort to rid me tank of annoying power heads and lower temps I am building a closed-loop water return manifold in my 55 gal tank (48l x 12w x 20h). <<Ok>> The tank is un-drilled so until I move out of this limiting apartment and upgrade I am sumpless (I refuse to use an overflow box with J or U tube because I would like my security deposit back when I leave). <<Heeindeed!>> I am building the system out of ¾ in. PVC tubing and fittings, and going down to ½ in. at the 45 degree elbows coming out of the Ts.  There will be 10 outlets (4 on the front and back and 1 on each side) with at least 3 or 4 of these being plugged up to allow for changes in flow when needed later on. <<Ahgood idea>> The pump is either going to be directly behind the tank for 0 head or on the floor below with 53 in. of head pressure needed. 1- I am trying to find out what size pump would be needed for something like this.  I am thinking in the 1200 to 1500 GPH range. <<Figure at least 250 gph per ½ nozzle, plus another 20% for the eventual bio-film buildup in the manifold piping and this means you need a pump that will provide a minimum of 1800gph after head-loss (This is assuming only six of the ten nozzles will be open at any one timeotherwise calculate as necessary)>> 2- Do you think this will be adequate or overkill? <<Will need to be a bit more in my opinion.  But do be sure to plumb a gate-valve on the output side of the pump to temper flow if needed>> The tank houses 4 damsels and a blue spotted sharp nose puffer (I know he is not reef safe but he is oh so cute and has yet to even looked twice at any of the corals  <<yet>>), various inverts and some corals (whose numbers seem to be increasingahh the addiction) 3- Also in purchasing the pump should I be purchasing one rated for pressure or one for free flowing circulation? <<I would consider a pressure-rated pump for the closed-loopthough a large enough non pressure-rated pump will work>> I am looking at the Japanese Iwaki pumps for more than one reason, choices are:  the MD40RLXT which is a circulating pump rated at 1,200 GPH, and either the MD55RLT for pressure rated at 1,080 GPH or MD70RLT 1,500 GPH.  What do you think of these choices? <<All great pumps but  The 70RLT should work if youre willing to cap off a one or two more nozzles than originally planned, but I think you would be better off getting the 100RLT for your planned configuration>> 4- Considering heat transfer and electrical usage do you think it is worth my time to also be looking at MAG drive pumps? <<The Japanese motored Iwaki pumps are fairly economical to run and also surprisingly cool in my experience and would be my preference here>>   I wont be having any other pumps running except the MAG 3 drive that is on my AquaC Remora Pro protein skimmer.  I would rather not be paying an arm and leg each month to run the tank, but I also dont want to make soup of my tank with super high temps, especially come summer time. <<Understood.  Dont discount the effectiveness of evaporative coolinginstall a couple fans to blow across the surface of the tank to help keep water temperatures down>> Once again thank you, Randy <<Happy to share.  EricR>>

Re: Return Manifold and Pump Size? 03/26/07 Hello again, <<Hello Randy>> Thanks for the advice given below. <<Hope it was useful>> I went ahead and got myself a slightly used Iwaki MD 100RLT from a fellow reefer to power the closed-loop (way too expensive to buy a new one). <<A good choice and surprisingly quiet for their size/flow-rate... in my experience>> I am about to upgrade to an Oceanic 72 RR bow front that has the mega-flow overflow and now some new dilemmas have arisen. <<Oh?>> Underneath I am going to be setting up a 10 gallon refugium that will be fed by a T coming from the tank drain w/ a valve to slow down the rate and then gravity flowing at a slower rate into a 10 gallon sump w/protein skimmer, etc. <<Ok...but rather see use of larger vessels if possible>> So now that you have an idea of the setup here are some questions that I hope you can help me with. <<I shall try>> 1. Do you think that the Iwaki MD100rlt pump is too much pump to be used as the return line for my sump? <<Gosh yes?!  The 1 drain in your mega overflow will only handle about 350gph before you start having issues...and it will certainly NEVER handle the output from a 2000gph pump like your Iwaki>> I am torn between attaching my manifold to the return from the sump, or using a second pump as a return and keeping the manifold and Iwaki pump on a closed-loop. <<The latter is your only choice here...with something like a Mag-5 for your sump-return pump>> 2. Considering that my manifold was made for a 55-gallon, three of the four sides fit perfect in the 72-gallon bow front, except obviously enough the bow side. <<Yes, but is this really an issue?>> I am contemplating getting some schedule 20 PVC and using a heat gun to bend the PVC into the curve needed to flow with the line of the bow and then cutting in where needed for the T's. <<I see>> Do you think that schedule 20 PVC will be strong enough to handle the pressures, and do you know if it is strong enough to be able to handle heating it up and bending it like I want to do? <<Yes to the first (I can see Bob cringing)...<I am. Use flexible instead. RMF> I have used this pipe myself (has a larger inside diameter than SCH-40 of the same diameter, i.e. allows more water flow) with good/reliable results on straight unrestricted runs, but I dont know that it has enough thickness for bending without becoming too weak/flimsy.  But it is cheap enough I think you should give it a try and determine for yourself...can always go with SCH-40 if need be.  Have you bent PVC before?  You will need to place some type of media inside the pipe when you go to bend it to keep the walls from collapsing...sand often works well and will also help to hold heat>> 3. In plumbing my refugium I am trying to figure out if I should have raw water from the tank flow into it, or skimmed water T'd off from the sump? <<Raw water from the tank>> Then depending on that, where I want the water going as it comes out of it; into the skimmer compartment or past it to be pumped up to the tank? <<Directly to the pump chamber to prevent the skimmer from removing plankton is my choice>> I figure it should flow past the skimmer to allow any living matter that escapes a chance to make it up to the tank and become food. <<Ah yes...so you do understand>> I am also thinking that is should be raw water flowing in because the waste from above can become food for whatever is living in the refugium.  Does my logic make sense? <<Youve already figured it out...yes, makes sense>> Thanks in advance for your input, Randy <<Always welcome, Eric Russell>>

R2: Return Manifold and Pump Size? - 03/26/07 In your statement below are you saying you would rather see one large vessel instead of two, or two larger individual vessels? <<Sorry for the confusion mate..."two larger vessels" was my intent>> My thinking in the two vessels is that I can have a fast turnover rate in the sump, and then a slower rate in the refugium making it a less turbulent area for whatever is in there. <<Am much in agreement with this logic...just wish you could utilize a bigger tanks for your sump and refugium (say 29g?)...but if not, the 10g will suffice>> I am limited by the stand to either two 10-gallons or one 20-gallon, so I came up with this plan. <<Understood my friend>> One 20 would be simpler, but I feel having the refugium in the sump compromises both...I would rather have a good sump and a good refugium then a mediocre combo. <<You echo my sentiments exactly re sump/refugium combinations...please proceed as you have planned>> It made sense in my head, but please tell me if my thinking is a off here. <<Not at all>> Gracias por todos, Randy <<Dé la bienvenida siempre a mi amigo.  EricR>> Combine Closed-Loop Intake and Sump Drain In Horizontal Overflow? 03/26/07 Hello, <<Howdy>> I want to first say I think your site is great and it has helped me a lot in planning my first reef tank. <<Glad it has been of use>> I do have a question though that has been somewhat answered but only in general terms. <<Ok>> I am hoping if I give you some specific details you can tell me if a closed-loop intake in my overflow will work quietly. <<Mmmm...Ill see what I can do>> I have a horizontal overflow that is 16 inches long and 4 inches on each side and 4 inches deep.  It will be mounted in the middle of my 50-gallon (36x15x20).  This will give me 24 inches of linear overflow. <<Agreed>> It does have teeth cut into it; the cuts are 3/8" wide and 1 1/4" deep.  I know the teeth violate the Calfo-principle but I had it made before I did all my reading here and would still like to use it. <<Ha!  No worries mate...am sure Anthony will forgive...>> I was planning on putting 4-1" bulkheads in the overflow.  Two would be used to drain to the sump, one would do, but I wanted some redundancy. <<Redundancy is always a good idea>> The other two would be joined with a wye to a single 1" flex PVC and go to the closed-loop pump, a Blueline 40 HD-X capable of 1270gph @ 0' head (1" intake and output).  Using a Mag-3 for the sump return, and the Blueline for the closed-loop, I am figuring I will actually flow no more than 1100 to 1200 gph.  If I used down turned elbows on the drains, will I able to drain this much water from the overflow and not suck in air or have a lot of noise? <<I'm not sure how this configuration will "balance out."  The presence of the closed-loop intake in the skimmer box will cause more water to be pushed/pulled in than you intend your "sump" overflows to handle.  And though the pump intake may be more "aggressive" than the gravity drains, I think they will still "drain" more water than you intend causing noise/bubble issues...and possibly even "starving" the closed-loop pump which could lead to more noise/bubble problems.  I think it will be better if you don't try to incorporate the loop intakes in to the overflow box.  This configuration would also recirculate much of the oily surface film through the loop, rather than letting it go to the sump for the skimmer to remove.  Since the design of a true closed-loop precludes the tank draining in the event of a power outage/pump failure, I recommend you drill/place the throughputs for the closed-loop "outside" and below the horizontal overflow box>> Should I just not bother trying this and just put two bulkheads in the overflow and drill the other two below the overflow for the CLS? <<Ahh, yes!...is what I would do>> Thanks WWM crew! <<Happy to share.  EricR>>

Closed-Loop Manifold Design Review (Anthony Calfo) 03/06/07 Dear Anthony / WWM crew, <<EricR here...Im afraid Antoine has moved on to other enterprises and no longer fields queries here...but hopefully I can be of assistance to you...>> Im in the process of setting up a 45-gallon tank that is 24X24 and 18 high.  I have a center back overflow, which due to a miscommunication now only has a 1 drain and a ¾ return as opposed to a 1.5 drain and ¾ return that Id hoped for. <<Mmm, indeed unfortunate...but still a workable configuration>> This tank is intended for Frogspawn and Candy Cane corals only, so Im shooting for about 500gph flow through the 1 drain and a 15 gallon sump. <<Is possible...but I always recommend about 300-350 gph maximum flow through a 1 gravity to simplify plumbing hassles (noise, et al)>> Ive narrowed my pump choices to either an Iwaki 20RLXT that will flow 450gph or a Gorman Rupp GRI 510 that will flow 550gph according to Reef Centrals flow calculator. <<Hmm, not the manufacturers stated flow rates...Ill assume this is the flow rate you have figured based on your plumbing configuration then.  Both are good pumps...with the GRI being pressure-rated and this particular Iwaki model not.  I think considering your 1 drain, I would opt for the Iwaki...and do be sure to plumb a gate-valve on the output side of the pump to temper flow as/if necessary>> The top opening of the tank is 17X16 and Im planning to have either 6 or 8 outlets from a ¾ manifold running along the perimeter of the opening. <<On a separate pump/closed-loop I hope?  Eight outlets from a ¾ manifold will require at least 4800 gph after head-loss (based on 600 gph per outlet to achieve meaningful flow)...and way too much for this tank as well. With the return pumps you have listed, you are limited to two ½ nozzles at most...and even then I dont think the flow from each nozzle will be vigorous>> a)       Do I have too may outlets? <<Yes indeed>> Im not sure how to balance flow per outlet with number of outlets.  Would I be better off with 4 outlets? <<Not really...the 1 drain on this tank can not handle the flow required to power a multi-nozzle return manifold.  If your goal is to keep powerheads out of this tank then your best option...in my opinion...is to plumb a separate closed-loop, or go with the two 1/2 nozzles as I previously suggested.  Which, considering your stocking plan, would likely be just fine>> b)       According to Reef Centrals flow calculator, changing the 90-degree bends to 45-degree bends has an insignificant effect on flow rate!!!???  Doesnt make sense? <<Mmm...their calculator also says you can flush 600 gph down that 1 gravity drain [grin].  I guess it depends on your definition of insignificant...but I definitely think easing the turns in the plumbing helps>> c)       Im planning on using an Aqua Silencer standpipe and I cant decide between the 1 version and the 1.5 version with an adapter to fit my 1 bulkhead <<These devices generally work better if slightly larger than the plumbing lines...I would use the 1.5 device if it will fit your overflow box>> d)       Is 550gph too much for my tank given the size and livestock? <<Not in my opinion>> Thank you for your help, Narayan Raja <<A pleasure to assist.  Eric Russell>>

Re: Closed-Loop Manifold Design Review (Anthony Calfo) 03/07/07 Thanks Eric! <<Quite welcome Narayan>> But I was hoping for at least 3 nozzles, min of 450gph and no powerheads in the tank. <<I understand...but at this flow rate you will be sorely disappointed with the output from three nozzles>> I have room to enlarge my drain bulkhead to a 1.25" size, but there is no such thing that I could find in schedule-40 bulkhead fittings unfortunately.  Is there such a thing...? <<Have a look at USPLASTIC.COM...they do have 1.25 bulkhead fittings>> Having a second pump and a closed-loop is complicated since my stand will have very little room left after the sump, pump and ballast. <<I see>> I forgot to mention one little detail -the 4" DSB which will reduce the tank water volume to 31 gallons + sump and it is for the DSB primarily that I'm concerned about having adequate flow... Sorry. <<No worries mate...and a valid concern re the DSB.  Perhaps you wont have a choice about adding a powerhead or two...>> Thank You, Narayan Raja <<Always welcome.  EricR>>

Re: Closed-Loop Problem...The "Meager Flow" Issue - 02/13/07 Good morning Eric and all crew, <<Hello Mark>> Thanks for all your help and info, I have also posted this info on the forum site. Re: Closed Loop problem  Posted: Feb 12, 2007 12:37 PM  Reply   Well I have made a few modifications with very impressive results. <<Excellent>> I have changed all of the output pipe from 0.5" to 1.5" and also removed the 180 degree U-trap at the connection from the pump output to the loop on top of the tank. <<Very good>> The flow rate is now very good, in-fact, a little too good. <<Ahh...so your intuition was correct...and now that I see the pictures I can appreciate the amount of restriction you had created with the 1/2" pipe>> I need to extend a few nozzles because they are to close to the surface and are creating a huge amount of turbulence and bubbles.  I think that this is due to cavitation. <<Yes...drawing in air>> I should have the 0.5" Loc-Line extensions in today and I can work on this tonight during "24."  Can I post a picture in this thread somehow or I suppose that I could just direct you to my photobucket site to view the pics - http://s27.photobucket.com/albums/c170/markkrysztofiak/ . <<Either way mate>> If it asks for a password, use: elections . Many thanks, Mark Krysztofiak <<Thank you for this follow-up.  Eric Russell>>

Manifold Questions 12/29/06 Dear Crew, <<Hello>> Your site is GREAT. <<A collective effortthank you>> Thank you for such an awesome resource and your time. <<We are happy to share>> I have some Q's re: setting up a manifold & related pump mechanics. <<Lets see if I can be of service>> I have a 135 gal. FOWLR w/ 1200-gph over-flow to sump and return to tank by 1100-gph external pump.  I'd like to use a 2nd external pump (dont want the heat/look of a submersible) for the manifold if possible. <<Ok>> I am looking at a Sequence Reeflo "Dart" pump, rated @ 3,600 gph with only a 160 watt draw.  I cant/won't drill the tank and dont really want a 2nd overflow. <<Well, that complicates things (though I dont recommend a siphon overflow for this application).  How do you expect to feed this pump?>> 1) I assume I can't use Dart from existing sump/overflow because the Dart's rating will overflow my tank unless I add a lot more overflow capacity? <<Indeedand even so, if this sump is located in a living space you would likely find the noise from the extra volume to be quite disagreeable>> 2) Looking at the pic below, can I avoid an overflow box by just setting the Dart below the PVC siphon line in the tank. <<I wouldntthese pumps are not self-priming, and anytime the pump stops your prime is likely to be lost>> I assume siphon would be fine once pump is running? <<Till a power outageand how do you propose to start the siphon in the first place?>> But, would this set-up maintain siphon in event of a power loss?   <<Is a gamble.  If all the manifold outlets are submerged you might be able to maintain the siphon but there is no certainty.  A gravity drain/below-water throughput is the only way to feed this pump in my opinion>> 3) If the pump is "self-priming", does this mean it draws the water from the tank and creates the siphon (or does the pump only push water that's already reached it)? <<Do double-check with the manufacturer, but Im pretty sure this pump is NOT self-priming and needs to be flooded to function properly>> 3) The pump has a 2" suction & a 1.5" discharge.  I need to take the discharge down to 1/2" for the manifold.  What effect will this have on the flow rate & the pump life? <<There will be some decrease in flow as the pump is not pressure ratednot aware/sure of effect on pump life, if any.  This is a popular pump for this applicationperhaps you could post this question among the users of this pump on the reef forums (reefs.org/reefcentral.com)>> I assume it decreases flow rate, increases water pressure and decreases pump life? Is this ok? (both for purpose of manifold & pump)? <<Yes to the first twoand the increase in pressure is a desirable aspect for use with the manifold>> 4) If my planned set-up does not work for reasons you will explain, can you please suggest how I would set-up a manifold with my 1200 gph overflow or is my only option a submersible? <<Hook the manifold up to the return from your external sump pump>> If a submersible, can you please suggest one? <<As in in the tank?  Perhaps one of the larger Mag-Drive pumps (24, 36)>> Any guess as to how much temperature would increase w/ a submersible? (I can't afford a chiller). <<Could be significant (4-6 degrees)>> 5) Any other help you can provide would be SO appreciated. <<You have two options as I see it Paul.  Either drill the tank to feed the additional pumpor simply design/connect a manifold to be used with the existing sump return pump>> Thanks for your help, Paul <<I hope it has been useful.  Regards Eric Russell>> Manifold Plumbing - 01/10/06 WWM Crew, <<Howdy>> Bob was kind enough to give me some feedback concerning a new set up a couple of weeks ago.  I'd like to see if I could bother someone with specific questions about plumbing a closed loop, water return manifold. <<No bother, shoot...>> Given the Oceanic RR 215 gal. tank is not plumbed to get anywhere near the 20 to 30 times volume per hour I want to support SPS corals, <<You wouldn't want this volume of water flushing through your sump anyway.>> I'd like to add a manifold system instead of using powerheads to accomplish this. <<A good approach.>> For all practical purposes, I'm considering the 600 GPH I'll be getting from the two 1 inch overflows as insignificant for anything other than operating the sump. <<About ideal for this, actually.>> I've looked at the data for the Sequence Reeflo Hammerhead (1 1/2" inlet/outlet) and see that the flow is 5400 GPH @ 5' head.  Since this is a closed system, am I correct in assuming the head will only be from the plumbing or do I still have to consider the static head (5' from the pump to the top of the tank) as well? <<Yep...and add a foot of head to that for about every 10 feet of horizontal run and again for each elbow/turn.>> At any rate, here are a couple of scenarios I have been thinking about.  Please feel free to give me my best option or suggest another if I've really missed the mark. <<Okey Dokey>> Drains:  1 1/2" PVC all the way to the pump.  My understanding is that the fastest way to burn out a pump is to starve it on the inlet side. <<True...not to mention wasting efficiency/flow.>> I will run pipe across the back along the bottom of the tank and have four 1 1/2" openings every 24 inches starting in one corner progressing to the opposite corner. <<Am guessing these will be protected with some type of screen/grate to keep from sucking up life forms?  Also consider how you will be able to access these later for necessary maintenance/cleaning.>> The pump supply will come up the back of the tank at 36" (halfway between the 2 corners), over the edge and down to the pump underneath.  In each of these cases, the drain design will not change.                        |  |                        |  |                        |  |                        |  | |  |______|  |___|  |___|  |______|  | |___________________________| -----------------------72"--------------------- For the manifold, I intend to use 3/4" PVC all the way around the top edge of the tank (72" x 24") with 14 to 16 - 1/2" openings alternating with 90 and 45 degree elbows to get as much water movement as possible. <<I see you've done your homework...necking down the nozzles allows you to keep water velocity up while allowing you to add more output locations.>> I figure this gives me about 350-400 GPH out of each nozzle for 29" depth of the tank. <<Excellent...you can always cap off a nozzle or two if you find it necessary.>> There has been some question as to whether I can move 5400 GPH through this manifold using 3/4" diameter pipe. <<Mmm yes, another reason to use a pressure-rated high-flow pump.  There will be some amount of back pressure related to the pipe diameter, but a pressure rated pump will handle this fine...and you need the pressure to power all those nozzles.>> Manifold supply:   1.  Single 1 1/2" PVC line running up the back of the tank beside the drain line to the manifold, bushing down to 3/4". 2.  1 1/2" from pump to the base of tank, tee to both ends of tank, horizontally, and up the back of the tank on both ends for two connections to the manifold. Any feedback concerning the best plumbing option <<I would keep it simple and go with option #1.>> or better choices concerning the diameter of the pipe at any point would be appreciated. <<I think you have all well in hand.>> I may be over analyzing this, because every once in a while I think ultimately, the manifold is only 3/4".  What do I gain by not bushing down the return to 3/4" from the pump, plumb it all with 3/4" and be done with it? <<This is viable actually, and would likely have little effect/make a small difference.  But may I suggest...  PVC pipe is relatively cheap, why not make up several configurations and test them to determine which you like/works best.>> Thank you again for the wonderful resource and all the help. Sincerely, Lance Good <<Good luck with your project, EricR>>

Understanding Closed-Loop Plumbing - 03/08/06 Hi all, <<Hello>> As per Anthony's suggestion, I am in the process of putting together a closed loop system for my 110 reef tank. <<Great!>> The tank is drilled for the main overflow to the sump and for the loop, I will be using an external magnetic drive pump. <<Okay>> I was just starting to wonder how I am going to get water into it?  I have looked around, on the web, and the best I can gather is that just like a canister filter would work, I will plumb with pvc up to the tank to suck water out <<Mmm no, not "suck"...you need to plumb so water will "flood" the pump...as if through a bulkhead in the back/side of the tank.>> I guess I will need to use some sort of screen at the intake correct? <<A bulkhead screen, yes.>> The returns will be a manifold of sorts around the perimeter with flex nozzles and valves for control.  Once plumbed up, do you just plug it in? <<Yep>> I remember from my freshwater days, needing to start the siphon on canister filters.....does that need to be done here?...or like I said, just plug her in and let her rip? <<No siphon, like I explained...you must flood the pump.  If you read through our FAQs on closed-loops this is/will all be explained.>> Secondly, is there a concern, for example like with your sump plumbing (overflow ) in the event of a power outage?  It would seem not, as like in a canister filter, everything is all sealed up?  Is this correct. <<Yes, but a "closed-loop" is not plumbed through the sump...please have a look here ( http://www.wetwebmedia.com/pbretfaq3.htm) and among the indices in blue.  Regards, EricR>> Understanding Closed-Loop Plumbing II - 03/09/06 Thanks, but since drilling is no possible for me to install a bulkhead, can't I plumb an over the tank?  Just like one would with an Eheim or Fluval canister? <<But you are not plumbing a "canister"...how will you prime the pump?...and if you lose siphon you will likely lose the pump (burn-out).>> I saw that link on Melev's reef and that seems to be what he had done. <<Are we still talking about a closed-loop?  I'm not familiar with the system/method you speak of but if you think it might work, give it a try.>> If so, how does one get the water to start flowing into the pump. <<Indeed, how?>> If I remember correctly, from my days of using Fluvals, one blows into the output end to start a siphon on the input end. <<Mmm, maybe...I just fill the canister with water and fire it up.>> I had planned on using a Blue line or GenX pump at about 1100 gph split into two returns and possibly reducing the returns from 3/4" to 1/2" in order to increase velocity and turbulence.  There is a main return pushing about 1200 gph straight through a 3/4 " return.  What happens in the event of a power failure with a closed-loop this way? <<If plumbed as a true closed-loop...nothing.>> BTW, the link you gave me did not work. <<Hmm, just gave it a try, works for me.  Please try a Google search from our home page re "closed-loop".  Regards, EricR>> Inlet for closed loop manifold  - 04/05/2006 Good afternoon WWM crew. <Trevor> I am currently in the planning stages of engineering a closed loop manifold for my 180 gallon AGA.  Through your extensive FAQ,  which is truly priceless, I believe I can successfully generate the manifold component and also appropriately "size" the pump for the desired flow rate in the display tank relative to head, horizontal run, elbows, tees nozzles. <Yay!> What I have not been able to clearly extract out of this wealth of information is the appropriate inlet size relative to desired flow rates in the display tank.  I have come across information on drain rates through bulkheads:   ~ 300 gph, 750 gph, 1000 gph for 1", 1.5", 2" bulkheads respectively.  Do these aforementioned numbers remain the same if one is "attempting" to aggressively pull water through the inlet with a pump or are they based on a  flow rate due to gravity's "pull" alone (my instincts tell me that if most inputs and outputs on external pumps are 1" that a 1"inlet  in the display tank should be able to handle whatever the pump is rated ... but I have been wrong before and I am sure I will be again)?   <Can't address the last adequately (is a great question/statement), but you are correct in questioning the intake sizes as stated if there is any restriction/vacuum consideration... that is to state, these diameters are idealized for no such restriction, including intake screening> If I have a 2" inlet in my display plumbed directly to the input of a pump of infinite flow rate what would be the maximum flow rate that  could be produce, for simplicity, at the output of the pump (I am assuming at some point the 2" inlet has to limit the pumps ability to intake water at a greater flow rate .... <Let's stop here: about 800-1000 gph...> or am I wrong and my flow rate is actually infinite gph)? <Ah, no. There are practical limitations, induced drag, sp3 hybridization, Brownian effects, affinities of water to contend with> I want to maximize the flow rate of my closed loop manifold using a 2" inlet from the display plumbed directly to an external pump, but I do not know what I can expect to maximally pull through the 2" intake. <The above values are about it in practical terms... one can (of course) pull/push more through a two inch diameter line, but there are other considerations, principally screening issues, that need to be addressed> Thank you in advance for the sharing of your knowledge and experience, again, it is truly appreciated.  Trevor <Is this clear? You want to avoid "sucking up livestock", cavitation, drawing in air... Bob Fenner>

Re: inlet for closed loop manifold   4/7/06 Bob, <Trevor> Thank you for your time in the reply to my question.  And as it seems standard in the FAQ's forum, questions beget questions. <Along with some clarity, resolution hopefully> Upon reflection I may have mislead you in my statement about appropriately sizing my external pump for my closed loop manifold in one area ... adjustment for static head.  In reading through Dr. Sanjay Joshi et alt. featured article "An engineering view of aquarium systems design:  pumps and plumbing" they mention at the end of the article that "a closed recirculation loop would have zero static head".  I do understand how this could be if an individual were to use a pump on the same horizontal plane as the recirculation loop. In designing my closed loop manifold, with your latest input, I feel that to I am now going to need to "pull" from three 2" inlets plumbing directly to my external pump to get the desired flow rate from my closed loop manifold.  This added plumbing will be lowering my external pump from the display water line by approximately four feet.  In my limited, albeit improving, knowledge of plumbing systems, I would be convinced this should be incorporated in my equation for total dynamic head.  Is this appropriate thinking, and if yes how have I misinterpreted Dr. Sanjay Joshi et alt. statement which would seem to contradict my aforementioned thought. <Mmm, don't know if I'm following you... just yet. But with the lines filled, no apparent low-pressure at the intake to the pump volute you should be fine here> I feel like the carrot is dangling right in front of me when looking through the FAQ's from 1/06 but again but I am just unable to decipher the simplest of things .... "yep"! Copied from FAQ on 1-6-2006: I've looked at the data for the Sequence Reeflo Hammerhead (1 1/2" inlet/outlet) and see that the flow is 5400 GPH @ 5' head.  Since this is a closed system, am I correct in assuming the head will only be from the plumbing or do I still have to consider the static head (5' from the pump to the top of the tank) as well? <<Yep...and add a foot of head to that for about every 10 feet of horizontal run and again for each elbow/turn.>> Is that "yep", he does need to take into account the five feet when calculating total dynamic head because it is a closed system.  Or is it "yep" he does need to take the five feet into account when calculating total dynamic head in his closed loop manifold. <Am guessing, but I think the responder is referring to "induced drag" not really "head" per se> Is pulling from three 2" inlets drilled into the back of my tank for my closed loop manifold an appropriate design.   I am attempting to supply an external pump that will drive 2400-3000gph out of my manifold. <This is a bunch of water/flow... to move through a manifold/aquarium...> I will also be using two of the bottom pre-drilled holes in my "reef ready 180 AGA" (ironic ... reef ready, yet I am looking at drilling?!!) <Yes. Necessary with this flow/profile> as returns from my 75 gal sump/refugium and the other two as drains into my sump/refugium (refugium turnover will be 4-6x).  The return form the sump/refugium will be generating another 1000-1200 gph for a total display circulation 3400-4200gph when calculated with manifold.  I am trying to maximize circulation in attempts to give appropriate care to SPS corals. <You'll do fine> Am I making my display into Swiss cheese or will it remain structurally sound in the above scenario? <? You'll do fine methinks...> Or would you it be more appropriate to replace an inlet with an internal pump to maintain above values? <I would skip on the internal pump/s at this point... Look into the Tunze line later if you see such a need> I would like to avoid the later, but I do not know if it is possible. <Is> Thank you and all the WWM crew again in advance for all your patience in sharing your knowledge with all who ask. <Mmm, I would utilize a "throttling mechanism" on the discharge side of your ext. pump for the closed-loop here... ideally an electronic-electrical one to save energy... that will allow you to adjust flow/pressure... Take care to situate your through-puts/drains sufficiently below water surface level to avoid cavitation, allow for screening, directing (perhaps thread by slip street els...). Bob Fenner> Return Manifold, Pumps...General System Plumbing - 03/11/2006 I was reading up on this method to get better flow but just had a few specific questions. <As vague as possible, please.> I have an 80 gallon reef tank and I hate the powerheads. I have a return from my fuge that is probably pushing 250-300 gph. I want to build a closed loop system to eliminate the phs. <Do you want a true "closed loop", or simply a return loop?> My tank is not drilled but it has a piece of glass at the top of the tank under the canopy that I can rest items on. <Better things to "fix" this in place.> My idea is to build a loop system with 4- 6 outlets with a pump that is rated for around 1000 gph but not have the pump submersed under the water. Is this possible and what are the cons of this system. <Quite possible. This is my preferred method of returning water to the tank.> Also what pumps that are available would be the best choice for my idea. <A shorter list to say which aren't...> Thanks for all of your help and your knowledge is invaluable to us novice reefers. Thanks Dustin <It's a lot to read I know, but I would go through our FAQ's until it hurts. A lot of different angles to take into account, but once you understand what not to do, the what to do makes perfect sense. Have you read the Calfo article re this? Grabs some toothpicks, prop open those lids, and let the coffee flow. - Josh>

Re: Return Manifold, Pumps...General System Plumbing - 03/14/2006 Thanks, I bought some pvc and started trying to negotiate all of the turns and filter and overflow and I think that it will end up being a pain rather than beneficial. <Hmm...Shouldn't be that bad.> I think I am just going to buy some new powerheads that actually get the job done. <If you hated them before, this probably won't change. But...> Thanks again. <Sure Dustin. - Josh> Overflow Questions   6/1/06 Hello Bob and the WWMC, <James with you today.> I hope all is well and Hawaii was fascinating (jealous). <Talking for Bob, Hawaii is always fascinating, something different on every dive, correct, Bob?> <<Mmm, yes, but back in sunny southern Cal. now>> I am starting to plumb my 50 gallon sump and refugium to my 150 gallon  all glass tank and looking for some expert advice. I will make this quick because I know you are all very busy. Is it possible to connect three separate hang on overflows (1) 900 gph and  (2) 1400 gph  to one central  3" drain pipe with vent? <Yes, a three inch drain will handle this, but why on earth do you need that much flow for a 150 gallon tank?  Problem is, if the pump is not sized close to the gpm of the overflows, you will always have problems with air in the "U" tubes.  So, at least a 3200 gpm pump would be needed...That's going to be an awful lot of water moving in your tank unless you are trying to establish a tsunami biotope. Ten to fifteen times the tank volume is sufficient.  You would be well over 20 times. Tell the fish to hang on for dear life.> The over flows  planned  positions are...  a 1400 gph at each end of the tank with  the 900 gph in the center. Thank you again for your time, <You're welcome.  James (Salty Dog)> Mark

Re:  Overflow Questions   6/1/06 Hello Crew and James, <Hello Mark> Thanks for the quick response. <You're welcome.> Hopefully these answers to your questions help clear up what I am trying to achieve. The return pump will be a Mag Drive 36 external , with a 1" schedule 80 pipe (true 1" I.D.) return to a manifold system. The manifold will have 8 outlets, if my calculations are correct I have 14 feet of head loss, total loss of 4.86 psi. Taking this into account, this leaves 852 gph of return divided by the 8 outlets,  which equals  106 gph at each nozzle. If you think it is necessary, I can branch off the return line and with another gate valve control the flow back into the refugium or skimmer chamber. Sump flow is as follows, skimmer, 3 baffles, refugium, 3 baffles, return. <A bit more clearer, Mark.  Think you should be fine here.  Do employ a gate valve at the pump to allow you to throttle down if necessary.  A return line back to the pump shouldn't be necessary.  If you want to double check your calculations, here is a link for you.   http://www.reefcentral.com/calc/hlc2.php James (Salty Dog)> Thanks Again for your time. <You're welcome> Mark Re: sponge filter in QT tank (saltwater)... and manifold pb  5/27/06 Great, thanks for the reply! Sounds like I should cut back on total amount I'm feeding or if I go with a Copper band B/F, I should look at trading him back in or leaving him in the 125 gal reef (if I get lucky and he doesn't eat too much of my corals). I have another question if I may, I put in a closed loop system in my 125 gal. (hooked up to a MAG12) I plumbed a manifold around the top of the tank with 8 outlets for lots of options on water flow direction. Would I be better off blocking off half of them so I get stronger water flow thus more turbulent action in the tank VS gentle flow out of all 8 outlets? Thanks again, Mike <Mmm, I'd get some slip plugs (insert, sans solvent) and push these in and see... may take pliers to extract... Bob Fenner> Refugium plumbing question   4/18/06 Hi Crew- <Ed> I'm a bit confused about the best way to plumb a refugium, sump and closed circuit return loop. <Lots posted re on WWM... and lots to consider... many "variations" on themes...> I'm planning on setting up a 90 G Oceanic Systems "Tech Series" Tank with two return overflows and two Megaflow accessory kits.  The system will be designed to ultimately house SPS, LPS, Clams, Mandarin dragonets and  Wrasses. <Not altogether compatible as you're likely aware> To ensure that all are well fed I would like to run a RDP  vegetable refugium with Chaetomorpha macroalgae and a 4" DSB so that I can grow  pods. Reef Invertebrates, Calfo/Fenner has an illustration  for a Downstream Refugium on Page 53.  If I understand correctly  the refugium should have a water flow of 5 to 10 times tank turnover.  This  would be significantly lower than the 14 time turnover I had planned for the  Calfo designed Closed Loop illustrated on the WetWeb site. How can I marry these two seemingly contrary requirements? <Two separate pumps, sets of plumbing... Bob Fenner> Many thanks, Ed

Re: Refugium, closed manifold recirc. plumbing question, reef stkg.  - 04/19/06 Dear Bob: <Ed> Thanks for your personal reply.  Perhaps I should have been more  specific in my selection of livestock.  It was my understanding that SPS,  Clams and a limited number of well chosen LPS corals could be housed together  and that Mandarin dragonets and Rainbow/Flasher/Fairy  wrasses were  compatible. Am I wrong? <Mmm, somewhat right and wrong... there are always induced problems with the mix of any/all Cnidarian species. Some much more grievous than others, and steps that can/have to be taken to alleviate these iatrogenic difficulties. Many LPS (an entirely arbitrary designation btw for many purposes), will consume dragonets... some can/will sting tridacnids...> I've been reading everything I could on WetWeb and other sources on  fuges but can't seem to find a scheme for plumbing these two separately. <Mmm, take them "one at a time"... entirely separate pumps, plumbing for each... You don't want to tie them together> I  don't expect you to do my work for me but if you are aware of a schematic for  such a system I would appreciate being directed to it. Complex plumbing issues are beyond my present level of  expertise. As always I greatly appreciate your work. Best regards, Ed <Please peruse here: http://wetwebmedia.com/marsetupindex2.htm Take your time, record good notes... read the files as they appear of interest, from the top, front to the bottom, right... down and across... The indices have been arranged by me in this order with purpose. Bob Fenner> Re: New 90 Gallon Setup... closed loop issues   6/13/06 Hello Bob,    <Scott>   Thanks for your reply.    <Welcome>   Based on the expert advice I have been getting (including yours), I decided to increase the size of my new system to 135 gallon. This will afford enough space for external pumps, and hopefully provide more options for (healthy and happy) fish stocking.    <Great>   Also, I believe this size should provide adequate space for my Centropyge aurantius (currently in quarantine and eating habits continuing to improve). Would you concur or should I consider finding another home for this beauty?      <In the wild this is one of the Centropyge species with a large "territory"... like many cichlids, it can be crowded a bit...>   In discussing the new tank configuration with a LFS, they suggested an enhancement which I would be very appreciative to hear your thoughts about (I did not find it addressed in the Circulation FAQ's in WWM and apologize if it has been addressed before). Anyway, here goes - The current setup would use 2 overflows to feed an Ecosystem 3612 (roughly 1200 GPH per the manufacturer) and back to the display. The balance circulation (say another 1200 gph) would be provided by powerheads. My LFS representative suggests doing away with the powerheads and plumbing a separate loop taking water from the back of the tank (about half way up the tank) behind the overflow boxes (the boxes would be equipped with Durso standpipes so that a water column would remain in them). The lines would be joined together to feed a parallel external pump and back to the display via 2-3 additional bulkheads located at the lower portion of the tank.    <Sounds like a plan>   I like the idea because it eliminates the "issues" with powerheads such as heat generation, exposed intakes, etc., but am wondering if we are drilling too many holes in the back of the tank. Would you have any thoughts to share on this?    <More holes can lead to more potential problems... if it were me/mine, I would not cut these through-puts quite so low... "just in case"... But near/closer toward the upper surface... not too close though, to prevent loss of water during change-outs>   Thanks again for your help on this project.      Scott <Glad to share. Bob Fenner>

Closed-Loop Plumbed Through Overflow? - 07/13/06 Friends at WWM, <<Greetings Scott>> What kind of problems would you foresee running a closed-loop and a sump out of the same overflow box? <<Hmm...would appreciate a bit more information to wholly understand what you are attempting. You'll need to plumb each to its own throughput/drain...you'll need to ensure the box can handle the volume of water/won't starve the pumps...and then there's the noise such flow/volume brings...>> Thanks, Scott <<Regards, EricR>> <RMF would NOT do this.>

Plumbing for a refugium & return manifold in 58 gal reef  - 09/14/06 Brent here.  Hope all the crew is doing well!  Basic background.  58 gal 36lx18,5wx21"h Tank.  Intended use:  Nice family project for my son, daughter and me.  My wife just shakes her head at our willingness to research, learn and spend bucket loads of money.  I'd like to point out that my 8 year old daughter is probably more enthused than me, and spends a lot of time searching the net for reef fish, inverts, and ideas to help the project out. <Well worth the investment all the way around>   She has even created her own little reef book complete with the fish, inverts and corals that she would like, noting common name, species, a little bit about the species, care, feeding etc along with a photo.  Beats shopping or playing with boys as she says! <Oh yes!> Anyway I digress.  Back to the issue at hand.  Reef display with some LPS and some soft corals,  mating pair of Ocellaris Perculas, Lawnmower Blenny, Royal Gramma, Six Line Wrasse, and a Flameback Angle added last, approximately 1 year after setup.  T5 - 6x39 watt hood.  I have a couple of general questions for completing the plumbing on my 58 gallon, sump and possible closed loop manifold.  Just working to fine tune the details and wanted to get your input.  58 has the corner MegaFlow overflow built in.  Wondering which manifold kit is better the Durso or the MegaFlow kit? <Mmm, the former IMO/E>    Megaflow kit has the return pipe and end fitting for the in-let and appears to be more complete with the perforated critter block for the inlet. <Can get, thread in such a screen yourself...> I have a CPR Large HOT refugium with maxi-jet 1200 that will incorporate MM with Chaeto and the CPR CF light unit. Lighting cycle in the CPR refugium to be on 24/7.  Although I'm not married to this photo cycle. <I would go with an overlapping RDP myself... Chaetomorpha should not be illuminated continuously>   I believe the CF is 19 watt?   I'm planning a 30lx14wx16 high sump/refugium with  4" DSB, sugar fine aragonite, a small amount of live rock to seed and Chaetomorpha algae with CF lighting 20 watt +/-.  Lighting to cycle in the sump/refugium off cycle from the display. I believe the actual refugium gallonage will be around 10 gallons, not including the 4" sand bed. I also have a CPR BakPak skimmer unit which I intend to have running full time.  I am planning to use a mag-drive pump, external, to handle the return which will simply be plumbed back up to the MegaFlow inlet pipe nozzle.  Just not sure if I should use the mag-drive 5 or 7 here? <Mmm... if it were me/mine, the 5>    I am also thinking of incorporating a mag 5 or 7 drive, internal, and creating either a manifold return closed loop with squid on 2 outlets or trying to incorporate Anthony's water return manifold http://wetwebmedia.com/pbh2oret.htm? <A good plan. The seven here>   Your thoughts and insight is well appreciated.  And thank you all for such a great site and willingness to help! <An enlivening pleasure to share. Bob Fenner>

Re: Plumbing for a refugium & return manifold in 58 gal reef. Not quite ready  9/15/06 Bob and crew, thanks for the quick reply!  In re-thinking just slightly.  I am contemplating using Durso overflows for both the 1" and 1/2" down to a sump set up to handle both overflow in 1" in the main sump and 1/2" to the refugium part with both overflowing baffles into a center return area (not using the 1/2" for the return) . <Let's take each of these items one at a time... I strongly encourage you to do a bit more delving... You (assuredly) do NOT want this small diameter overflow lines... too little volume, intermittent siphoning effects... and gurgling noise the likes of which even the Jolly Green Giant and a massive bottle of Listerine can produce!!! Please read here: http://www.wetwebmedia.com/dursopipefaqs.htm and the linked files above...> I can then place a pump external if I box into the return area to allow the pump to be exterior or place pump inside (although heat trans may be an issue)?   <May be... depends largely on the make, model... and size/volume-flow of pump used...> In incorporating both the 1" and 1/2" for overflows I can return back with a mag-drive 9.5 or 12? <Not necessary... this pump can/will "out pump" more than these lines can/could deliver... My friend... please... read...> and was thinking of utilizing the SQWD for alternating return current with 2 ever-tank-directable nozzles about 1" below the water surface.  Does this seem best to incorporate the overflow using the 2 drains and return over the top or separate as I noted in my design before. <Mmm, no... better to use one line of good/decent diameter and all-plastic valves to regulate flow... overflows w/o will prove to be frustrating...> Although the combined, rearranged sump will allow the extra flow, this will provide for a considerably smaller refugium.  Your thoughts? <You need... to read. Bob Fenner>

Sump/Manifold Plumbing - 09/13/06 Hi again folks. <<Howdy Jim!>> I am smack in the middle of setting up my new 150XH reef (I know, it's a tall tank, but there were reasons), with a 40G Breeder sump/refugium. <<Cool!>> This was a very hurried job after my 72G bowfront sprung a major leak, <<Yikes!  Been there myself mate>> but now that the fish and corals are all (relatively) happily settled in their new home (instead of Rubbermaid tubs in the middle of the living room floor), I am considering how to redo the current temporary plumbing into something more permanent and helpful. <<Okay>> The tank is a predrilled/overflow tank from Perfecto, with one corner overflow (I had anticipated two) which has a drain and a return fit with 1.25" bulkhead fittings. <<Mmm...better than the usual 1" I suppose>> My original plan was to run the 1.25" drain through a bushing, down to 1", and directly into the input of my Poseidon2 Vortex Venturi skimmer sitting in the first 9" compartment of the sump, probably without even using a pump--just let gravity drive the skimmer.  Assuming I manage to achieve the right flow rate, which, based on the pump that came with the skimmer, should be 700-800 GPH, does this make sense, or is it a crazy idea? <<You will never achieve 700-800 gph with a 1" (bushed) gravity drain my friend...expect something closer to 400 gph.  But from what I can tell from a quick scan of the NET, this skimmer is not a "recirculating" and thus won't work by simply feeding water to the skimmer body.  This skimmer needs to pull water from the sump through the venturi pump to operate properly>> I was hoping this would assure 100% skimming of the incoming water, but I can just run the drain into the compartment and use the Via Aqua pump that came with the skimmer to drive it, if that makes more sense. <<This is what you will have to do>> Then through triple baffles/bubble trap (the idea for movable compression baffles was a huge help) into a 20"x18"x12" lighted refugium compartment with live rock, DSB, and macro-algae, then into a 7" return compartment with a MAG-12 return pump and a float valve for automatic make-up water. <<Sound fine>> I was then planning to run the output of the MAG-12 into a SCWD (by way of a union and a ball valve), and run one side of the SCWD into the pre-drilled return, adding an over-the-wall 3/4" adjustable return at the other end of the tank to achieve some random/surge circulation. <<I would use BOTH throughputs to feed the sump...one "may not" handle the flow from the MAG-12...at least not quietly>> I was then also planning to add a couple small powerhead driven circulation devices in the back, using a design I found on Reef Central that uses PVC to keep the powerhead up out of the tank and in the canopy where it doesn't add heat and can be maintained (strainer and PVC up to the powerhead, then PVC back down to the location where circulation is desired). <Hmm...have not seen this...>> Now that I've done some reading about plumbing on the site, I am questioning the entire plan. <<...?>> First, I am wondering if this would be enough circulation.  I figure the MAG-12 should be pushing about 900 GPH at 6' head. <<Will be quite less after the SCWD...but still possibly more than the single return will handle efficiently/quietly>>   Adding a couple 200 GPH auxiliary circulation devices would bring my total to 1300, or 6-7 turnovers per hour.  Given what I have read, that doesn't sound like a lot. <<Maybe go with some 400 vs. 200 gph powerheads>> Of course, I know it's important to consider what I am keeping, which is all LPS, mostly Euphylliids, Caulastrea, and various brains and Fungiids, none of which particularly like very strong current, correct? <<Not really...they will appreciate some good flow...but not being directly blasted.  It will likely take some finesse on your part>> Furthermore, it sounds like the SCWD would seriously reduce the flow rate of my return, and I don't think I want that. <<Indeed...maybe as much as 20%>> But the present, single laminar return is definitely not working.  I was considering running my return into a manifold, but it sounds like the return wouldn't begin to have enough flow to drive a decent manifold, so I would need to install a second, closed loop system. <<Agreed>> I don't have any intention of taking the tank down to drill additional holes, so would it be possible to run a closed loop manifold without drilling? <<I wouldn't>> An internally positioned pump? <<Love those Tunze Stream pumps>> I can't imagine an overflow would work to drive a manifold! <<Not recommended>> How can I achieve decent, non-laminar flow with the present tank system?  Any advice will be appreciated! <<Why not use a "smaller" return pump (returned over the top) and use one throughput for the sump drain, and the other throughput to feed a closed-loop?>> Jim Jensen <<Regards, EricR>>

Flow Rates/Tank Turnover/Plumbing Confusion - 08/10/06 Hi, <<Howdy>> I used to have a 72Gallon Bow front tank set up but had to take it down. Now that I am setting it back up after a couple of years I had some questions on turnover rate and setup. <<OK>> I did read "Water Flow, how much is enough?" by Anthony Calfo and found it really useful.  Since my tank is empty I have the option now to drill holes, plumb the way I want and get a quieter pump.  I had a GEN-X 40 that will be my backup but it was too loud.  I was shooting between 10-20X turnover. <<A lot of water to process through your sump...can be done, but usually requires some effort to get things flowing well/quieted down>> But while searching various web sites and talking to people I was advised that I only need 3-5 times turnover through the sump and I should just add a closed-loop to make up the rest. <<This would be my recommendation as well.  This flow rate through your sump will be MUCH easier to manage>> Some say over skimming or reduce bubbles or noise etc. <<...?>> Some said it is not required in the sump or fuge.  Is this correct? <<Is what correct?  I'm not sure what you are asking here, but if you mean 20x tank turnover through the sump then no, this is not "required">> It's been a couple of years so I want to make sure things have not changed. <<Mmm, the hobby is changing/progressing all the time...but fluid dynamics won't have changed>> Also I was going to put on a Sea-Swirl for more water movement.  I was not sure if one in the middle of the tank or two on each end would be better. <<Will depend in part on how big (flow rate) a Sea-Swirl you opt for, but generally speaking, one at each end of the tank would be best for good coverage/flow throughout the tank>> But they seem to only be on the surface so my thought was one in the middle and have a Tunze Turbelle Stream Pump lower in the tank (ever use these? Are they good?). <<This configuration too could work...and yes, I am familiar/use Stream pumps in my 375g reef tank...an excellent product in my opinion>> Based on that I can then drill the back for my overflow in the corner or middle.  I have a lot of options and need some help thinking this through. <<Glad to proffer my opinions>> a) One or two sea-swirls? <<Two>> b) Placement of overflow? <<Center...with a minimum 1.5" drain and 1" return>> c) Sea-Swirl(s), closed-loop, or from sump return? <<For a high flow rate/water movement...the Sea-Swirls (or Tunzes) or closed-loop>> d) Where to put the Tunze (opposite of overflow if in corner? or opposite of return from sump if not sea-swirl)? <<Either option is fine>> e) Where to put the return from sump if not sea-swirl?  Corner, middle, opposite side of overflow? <<Wherever it is needed to provide/augment flow based on your other configurations>> f) Does the closed-loop get water from the overflow?  Or do I drill back as source? <<The closed-loop pump will need its own "source">> Or add PVC with holes hanging in the tank. (hope that makes sense) <<For the closed-loop intake?  Mmm, best to drill a bulkhead>> g) Pump Velocity T4 at 1275GPH - but with 4ft head and 3 - 7 90's depending on how many returns I have.  This is not a pressure-rated pump but according to the flow rates I would get between 1080 - 900gph depending on the how many 90's I have.  Is this enough? <<For which application?...it is more than you need for the sump return...likely not enough for a closed-loop>> Do I need more and should I have this split to two returns? Thanks, Jason <<Theres much to consider my friend, please have a read through our plumbing FAQs, here's a good place to start ( http://www.wetwebmedia.com/plumbingmarart.htm) and be sure to follow/read among the links in blue.  Regards, EricR>>

Manifold Plumbing   8/8/06 I have a 215G reef ready aquarium that I'm just starting to setup for a FOWLR and perhaps some hardy soft corals such as mushrooms. I didn't get the aquarium drilled for a closed loop due to the aquariums location, it is sitting on a stand that was custom made to fit in with a wet bar, without easy access to the rear of the tank should a bulkhead or plumbing fixture ever failed.  I was planning to just use powerheads, hidden as much as possible behind rock work, to make up the additional flow that is needed. I now have an idea to make a manifold at the aquarium top, such as that in the article by Anthony Calfo, and using an internal submersible pump instead of an external pump. I'm figuring that I can hide one larger pump behind the rock work in a corner of the aquarium that will not be easily viewed. I can make a stand to keep it off the bottom, and build a cage for it out of black egg crate and gutter guard to help keep invertebrates safe.  Using black pvc piping, I can return the water along the edge of the overflow making it less visible.  This way I will not have multiple powerheads to hide, and I will only have one pump in the aquarium on which to perform periodic maintenance and upkeep.  The aquarium is situated in a basement that averages between 66-68 degrees, even during the summer, so I don't think heat buildup in the tank should be an issue, in fact, I can probably use the additional heat.  I can also run the same pump as I will use to return water from the sump.  This way I can purchase a third pump as a backup for either of the other two in case one fails.  I have been running searches on the Internet, and your site, trying to find an example of someone using a similar setup, but I have not had any luck. Can you please let me know if this sounds like a plausible idea?   Thank you very much for your input and suggestions. <Sounds like it would work out OK.  You may consider installing a SCWD Water Director (Wavemaker) on each of your returns.  Less work with a nice wave making effect. See here.   http://www.drsfostersmith.com/product/prod_Display.cfm?CatalogCustomerNum=&catalognum=&pCatId=10668&prodId=20229&catId=1137745&siteid=6 James (Salty Dog)> Kevin

Aquafuge pro and closed loop circulation 3/2/04 Adam,  No doubt about it I'm going closed loop for circulation. The biggest concern I have right now is drilling the back of a brand new tank for the intake to the pump. You know the feeling you get when something is brand new and you think you'd like to tinker w/ it but you need a push in the right direction? What I'm looking for here is a vote of confidence. <This is definitely a scary thing!  If you do decide to drill, I would seek the advice of the tank builder and/or someone local who has experience.  Aside from the risk of damaging the tank during the operation, you must be conscious of not weakening the structure of the tank and risking future failure.> My plan is to place a bulkhead w/ strainer about 8-10" from the bottom on the back panel for intake. <The lower you place the hole, the more water you can potentially lose if it ever leaks.  Consider placing the hole higher and using plumbing to get your intake where you want it.  It can be hidden in aquascaping.  Do also consider simply plumbing the intake plumbing up and over the lip of the tank and into position (no drilling required). Now, reading about all the pumps out there and their different intake sizes leads me to another question: what size opening should I drill for 1400 gph flow? I have eliminated 3/4" so far, also eliminated the SCWD in the line because of it's 3/4" input/outputs (just murdered my flow rate). What I will end up w/ is a 1" manifold 4-5 outputs. Should I select pump first and then match input size? Marine tanks are not new to me, every aspect of plumbing is. <1" bulkheads should be adequate for 1400gph, and will match most pumps in this flow range.  Purchase and measure your bulkheads to determine the required hole size.  There is often some size difference between brands.  Even if the pump has 3/4" outlet (Little Giant may), I would use all 1" plumbing for max flow.> Thanks, Sam <Best Regards.  Adam>       - Plumbing a Closed Loop - Hi - My question (today) is about plumbing a closed loop system.  I looked through the FAQ, but didn't really find anything to address this question. I have a 180 gal acrylic tank that is 60" long, 30" side and 24" tall.  It has two overflow chambers on each end, 8" square each.  There is a "coast to coast" overflow 4" square across the whole back of the tank that flows into the overflow chambers. I drilled holes for bulkheads for a 1" Durso standpipe for outflow to the sump in each of the overflow chambers and a 3/4" return that is piped through the overflow chamber and into the tank itself.  Although I drilled each overflow for a return, I'm finding that one 3/4" return from my Iwaki 40RLT pump is sufficient. The second overflow is turned off at the ball valve.  I had wanted to use an 1 1/4" outflow, but found that I could not get elbow of the standpipe into the chamber.  The 1" seem to work fine, so that's not an issue. Now for the question - I have a Dolphin 3600 AmpMaster pump and a Haywood Electrical Ball Valve to create a closed loop system that will change flow as the ball valve swivels from right to left sides. <Hmm... just a word of caution here. Do observe carefully your pump's interaction with the ball-valve - my feeling is that the switching between the two outlets will cause back pressure on the pump.> Both the pump and the ball valve have 1 1/2" input and returns. I have room in the overflow chambers for one more 1" bulkhead that I can to tie together and with a 1 1/2" tee underneath the tank.  But I'm concerned that I'll be pulling too much water through the overflow chambers and unless I get the standpipes exactly the same height, I'll "starve" either the closed loop system or water flowing into the sump. <Possibly - if you haven't already, I'd go through a wet-run/leak test - just fill the tank with fresh water to make sure all works according to plan.> The other method is to pull the input for the closed loop from just below the 4" square coast to coast. <Perhaps a better idea, although plumbing failure will cause a good deal of water to drain out - how about a bulkhead in the coast-to-coast?> The return from the Dolphin will go to 10 - 1/2" Loc Lines.  I'm also not sure whether it's better to drill two 1 1/2" bulkheads in the back of the tank for the returns and have 1 1/2" to 1/2" tees inside the tank or to have the 1 1/2" to 1/2" tees outside the tank and drill  for 10 1/2" bulkheads in the back of the tank (I'd also do this as close to the coast to coast as possible - just in case one leaks I want to try to minimize water loss). <More holes will weaken the tank - I'd go with as few holes as possible.> By having the 10 holes in the back of the tank, I'm taking up less tank real estate by not having a lot of visible plumbing along the back of the tank.  I'm not too concerned about drilling ten holes - I've gotten fairly good at drilling acrylic :-). Thanks in advance for the answer. Steve <Cheers, J -- >

Plumbing Manifold 8/12/04 Hi Crew, <howdy> My name is Keith. I have a couple of questions concerning Anthony's plumbing manifold. A little history first. My system will be a 125g main tank, 15g sump and 30g refugium. The tank is up and running (sort of). I got into a salt tank with too little knowledge and have had some problems.  Copper in my water and poor water flow were the two main problems. I <the latter is a very (!) common mistake. The minimum should be 10-20 X turnover per hour. You will likely need 2000-300GPH turnover here> I have corrected the copper issue. I have to take my tank down, get rid of the substrate and (at one time) live rock. Currently the only overflow is a HOB with one 1" U tube. (LFS said was plenty - yea right) I have found some one local to drill my tank for me. <excellent! A drilled overflow is the best/safest> Now for the questions. 1) Do you recommend drilling the bottom of the tank or the back for overflows?. <always the back... I still cannot fathom why some folks recommend drilling the bottom. It is harder to plumb around, requires an awkward/large standpipe or overflow tower... and is simply an unnecessary risk. The high vertical (back usually) walls are best, safest and most discreet> 2) Will two 1.5" overflows be large enough?. <not sure... is this the bulkhead size or the drilled hole size? If the former, that would mean your drilled hole is around 2.5". Moreover... simply determine how much flow you want (2000-3000PGH) and compare against the bulkhead mfg.s specs (like at Rainbow Lifeguard plastic website). This is the only way to safely rate it> 3) This is the main question(s) - if I use Anthony's design for a manifold does the return need to come from the bottom or back of the tank?. <the manifold is to be fed by the sump return pump likely. Else an in tank pump> Once I get the return to the top of the tank, will the manifold be above the overflow box's or do have to use elbows to go around both box's?. <whatever is practical... I cannot say as I do not know where the overflows are placed. The manifold typically sits just at or slightly above the water surface to be discreet> The last and final question has to do with balancing the flow from the nozzle's. I will be using a T4 Velocity pump rated at 1250gph with 1" intake and output lines. <this is very little flow/pump for a manifold. Just imagine if you have six nozzles fed by this pump working at head... that's less than 200GPH per nozzle (weaker than the smaller powerheads). A dismal water flow. Beef this up, mate> I was planning on having ten nozzle's in the manifold, 4 in front and back and 1 on each end. <ten nozzles sounds excellent for the tank to improve water flow and reduce detritus, etc> Will I be able to get enough flow through this manifold that the front nozzle's have a good flow of water?. <not enough> Thank you for your time and all the good information I have gotten from reading for hours on your web site. Keith <I wish you the very best of luck, my friend. Anthony>

- Plumbing a Return Manifold - Hello and thank you for all previous advice.  I am in the process of creating a return manifold like the one Mr. Calfo has posted.  I am planning on using a Blueline 200 with 1" inlet/outlet.  I plan on using 8 T's in the manifold and use adapters with swivel nozzles to finesse circulation. Question 1: Since pump outlet is 1" should the whole manifold be constructed with 1" pvc? <I'd plumb up to the tank in 1"... for the manifold perimeter around the tank, I'd use 3/4".> Question 2: I would rather support manifold above water line/above tank center brace and extend T's and nozzles below water surface for aesthetic reasons. Any issues with that? <Not that I can think of, provided you put a check valve in the main return line, before the manifold.> Question 3:  I don't want to drill the tank but would rather plumb inlet from display-over rim-down to pump.  Problem? <A huge one... would create a siphon.> If not, as I understand it, or maybe not, in case of power failure, since this a closed loop (no sump) method there is no chance of flooding, correct? <Didn't realize this was a closed loop, but still must make an allowance for a leak in the plumbing/pump. Siphons are big potential trouble.> Question 4:  Scenario--> power fails resulting in inlet plumbing over display rim drains back to display creating a air gap but there is still water in vertical pipe above pump.  Will this be enough water to prime the pump when the power should happen to come on again or will I burn up the pump trying possibly creating a fire and burning the whole house down b/c I didn't want to drill the tank??? Duh <Hmm... good question and something I would test once you have the whole thing built. Do think that if you use the check valve inline on the return, you should have enough water remaining in the plumbing to prime the pump. Again, would test this to be sure.> Thank you for guidance and patience. Avid reader <Cheers, J -- > Loop Manifold questions 4/21/04 You really do burn the midnight oil!  <At times like now (post and pre-travel)... yes, very much so <G>> Thanks for your dedication and suggestions! I have a couple of follow-up's. This tank will start off as FOWLR, but since I'm constructing it, I want to plan for eventually going reef with it. If I dedicate a pump to the closed loop, then I wouldn't need to go with 3 2" upper back wall bulkheads as these were intended to provide enough drainage for high turnover through the sump to display. In other words, would you simply put a pump behind the back wall display (below intended water level) with one bulkhead for input and then connect to the perimeter loop?  <Yes... this works best for most folks and is exactly what I am doing for the next/latest personal display tank of my own being set up> If I only have one input to loop pump, fully submerged bulkhead, what would be the impact on noise level, or would you recommend the loop suction side of bulkhead not be fully submerged for maximum silence? <Hmm... I'm really not sure what you are asking, mate? If the pump draw is flooded (below the water line and gravity overflowed)... then the noise of the closed loop with effluents at or slightly under the water surface will be minimal - relatively speaking> Would you still recommend a sump? <Yes... they are quite convenient for so many reasons> What sump to display turnover is recommended?  <Slow is OK here to minimize salt creep, noise, etc: 5-10 X would be fine> Any recommendations on a dedicated loop pump (which in this scenario would have close to 0 head)? <Iwaki (Japanese made) is still my first choice... then Sequence pumps are my second choice presently. kindly, Anthony> 

Closed Loop Manifold... Good morning!  My husband and I are preparing to set up this closed loop manifold (maybe just one pipe in back across the whole back) in our 90 gallon acrylic. We checked with LFS man who had the tank made for us. He said that all drilled holes and bulkheads can handle the new GPH; we just have to change what he called the spur fitting. We are considering either the Pondmaster¹s Mag Drive 18 or 24. With one, considering the overhead, it will actually be about 1200 GPH and the other, 1800 GPH.  So 10 x's or 20 x's the turnover... hmmmm..? Questions are:  1. Anthony states in his article that 6 tees for return water is max for 100 gallon tank. Could I have more? <Yes... of course, any given flow rate, pressure will be diminished per outlet in terms of outflow with increasing number> 2. My husband talked about using a smaller PVC pipe to "pinch" the water to increase flow. Much like a plumbed house. Main line coming in is bigger and then goes to smaller to increase the pressure. Is this o.k.? <Yes... a good idea> 3. And basically, how do you make sure you are utilizing the max GPH and not causing back pressure because you used too few holes? How do you make sure you don¹t have too many holes thereby making the pressure too gentle coming out and thereby losing effectiveness of the reason for manifold? <Mmm, can be done mathematically or by assay (actual practice)... my advice is to go the latter route... Not gluing/solventing pipe, fittings on the inside of the tank... looking at the resultant flow with the pump on, tank filled about all the way... experimenting with changing out diameter, number of fittings... until you have about what you want, what you're going to get... taking all back out, apart, drying, gluing together...> The rest of the information provided seems easy enough. These are my only questions....except, as you answer them I'll probably find more! Ha. Thanks. From MI <Welcome. Bob Fenner>

Closed Loop Manifold 4/14/05 Anthony, I'm planning to build an aquarium out of glass 72"L x 30"Wx 24"H 1/2" glass. I have planned to use 3 2" bulkheads (top back wall of tank) draining to a sump. I plan to use a Sequence Hammerhead for the return pump (approx head 18ft). Sequence suggested 2" piping off the return (in order to maximize flow vs. pressure)... <Yes... understood> ...which means I would have to go from 1.5" (discharge) to 2" up to the tank at which point I wanted to do a closed loop around perimeter of tank.  <Good> I have been told that the water level should not be over the 2" bulkheads. In other words maybe half up the bulkhead to reduce noise.  <Quite correct! For safe running/operation, do not overdrive the drains to the point where their running level is half of their capacity or greater (too noisy if nothing else)> My problem and hence questions have to do with how to configure the piping.  <The Closed loop pump in this case should be on its own drilled loop, and not tied into the sump> I have to put bracing all the way around the interior top of tank, but also take into account room to place the 2" pipe going around the perimeter (which will reduce to 3/4" for outlets), and try to keep the bulkheads slightly above the intended water level (otherwise the loop will run into the bulkhead baskets or bracing or.....), and also consider how to put a glass cover (lid/lids) over this whole set up. What suggestions, concerns, changes, etc might you suggest to make this work?  <From what little information is provided, I see no problems> Also, any suggestions on where to obtain black silicon for putting together an aquarium?  <Google until you can't Google no more <G>. And the big mail order companies perhaps like MarineDepot.com, CustomAquatic.com, ThatFishPlace.com, etc.> Many thanks, you guys are the best! <Kindly, Anthony>

Pump Sizing/Plumbing For A Teed Manifold - 05/21/05 Hello, <Hello Frank> I have a 135 gallon reef tank, currently running a Gen-X 1190 GPH return, and I have two 1-inch drains in the lower back of the system feeding into the sump. <Couple thoughts/opinions here Frank.  First - Be careful not to overestimate what your drains can handle and plan accordingly.  Many claim 600 gph for a 1" drain, and under ideal circumstances it will probably handle it (albeit noisily), but I've found that a "safe" flow rate for this size drain is about half of what's usually recommended.  Be aware that flow will eventually start to restrict due to growth of algae and cryptic organisms within the opening/drain pipe.  Second - You mention the drains are installed in the "lower" back.  Unless you have some type of riser pipe/overflow box installed, your tank will drain to this point when the pump is off.> My question has multiple parts: 1) Is my Gen-X giving a sufficient rate of turnover to my tank in general, and is it powerful enough to give decent flow to a teed manifold with six or so outlets, enough that I can forget about power heads? <On its own, no, even before accounting for head loss.  Some suggest a minimum of 10x total tank volume for flow, I feel more is better...20x plus.  When figuring number/size of outlets for the manifold figure 400+ gph for each 1/2" outlet and 800+ gph for each 3/4" outlet on the manifold.  Its my opinion your current pump would limit you to two 1/2" outlets on the manifold.  With a proper pump/manifold design (much covered in the FAQs), yes, you will be able to forgo power heads.> 2) If not, what should I upgrade to and will this require   additional holes cut in the tank for drainage? <Assuming six 1/2" outlets, you're looking at a pump in the 3000 gph range before head loss.  As for your drainage holes, I would plumb the two 1" drains directly to the pump and create a "closed-loop with the manifold.  You really don't want to try to push this volume of water through your sump.  Add another 1" drain and plumb the MAG 5 for your sump return.> 3) I am running a 500 GPH Mag 5 (and plan to add a second Mag 5) inside the tank at the moment.  Between this and the return pump am I giving respectable (I know it is not ideal) water turnover for the size of my system? <Could be made to work, though the manifold is a much better idea.  Be sure to adjust all flow output to interact in a random turbulent fashion.> Lastly, I know the answer to this could potentially fit under multiple categories on your website, could  you please post it under Plumbing 18 FAQ so I can find it easily. <I don't make the actual postings on the site, but be aware you get a reply returned directly back to you as well.> Much Appreciated, Frank Janes <Regards, Eric Russell>

Closed Loop Hey Crew! <Ben> I've Googled and surfed and can't seem to find a simple definition for a "Closed Loop" circulation system and/or a diagram of the principle. Please Help! Thank You, Benjamin <Mmm, some pix here: http://www.wetwebmedia.com/pbh2oret.htm and the linked files above. This is a "closed" as in not open (to the air) recirculation system for moving water around with a motive force (pump) located outside an aquatic system. Bob Fenner>

Re: Closed Loop Reply to Bob Bob: <Ben> Went to the link you suggested and all I saw was a pic of a closed loop manifold. <Please see the rest of the response... the linked (Related FAQs) files above...> I think my question regards closed loop for recirculation of water in tank for flow purposes. Pumped into tank and pumped out of tank <Mmm, no. Not pumped out... gravity, siphon fed> on a separate pump ergo CLOSED LOOP? If I am correct then how does one plumb for sump/refuge/protein skimmer when utilizing a closed loop system for increased flow? <Separately... not on or with a closed manifold> Strange to tell but I've been bopping along thinking closed loop =no fresh sea water coming in from ocean  hence water pumped into tank/overflow out of tank to sump= closed system. But it seems I have misinformed myself and wanted to assume nothing. Thank You Benjamin <Sorry for the confusion. Take a look at the Related FAQs files. Bob Fenner>

Re: Closed Loop continued Bob: <Ben again> Ok, I think I have a handle on what a closed loop system is now. One pump is dedicated to taking water from the tank and returns it to the tank with no stops (processes in-between). Purpose being internal tank FLOW (turbulence?). Then another pump returns water to the tank from the sump, the tank overflows into a return system and back to the sump it goes. Am I correct? <Yes> If I am on the right track then I have some concerns. I was taken by your idea of a weir (a glass plate in the back of the tank fixed at a 45 degree angle to the back plate) mainly for its ability to skim the surface efficiently and provide QUALITY protein rich water for the skimmer. My general plan is to feed the tank from the sump with 4 2" pipes .(one of which would be reduced to 1"  or 1.5" for a return manifold and another 1" branch off of a different  2" for refuge return) and overflow drained with 4 2" pipes. Powered by a Super Amp Master 7500 or something close to its capacity of 6900 gph @ 4'  head with 2" inlet and outlet. <This is a big pump...> Tank would be 180gal with a 100 gal sump and an independent 55 gal refuge (all with 6"DSB) mounted to the side but above the main tank My guesstimate is that total water displacement will be aprox.. 40%, leaving aprox. 200 gal. of actual water capacity. Estimated turnover to be somewhere in the 28 to 34 times per hour range. With that information as a background MY QUESTIONS ARE: 1) Since I've never seen a configuration like this actually run what is your sense of the flow and turbulence that will be produced in  the tank. Will the critters and rocks be flyin' around or just happy in the current? <With "proper", "adequate" dispersion the latter. Not much of this water is going through the refugium I hope> 2) Will such turbulence defeat the proclivity of protein and other waste products from residing at the  top of the water thus defeating the beautiful idea of quality water for the skimmer? <Not practically... such phobic molecules make their way past, into fractionators in due time in any, all cases> 3) Would such a turnover eliminate the need for a closed loop system? <Likely so... though I would rig a manifold for distribution of the return water> 4) Would one 2" fixture (the pump) feeding 4 2" pipes greatly reduce pressure? If so perhaps I should think of only 3 or 2? <I would use one... return pipe... two inch bushed down at the over or through tank fitting to one inch tees... Do take a read through our plumbing article, FAQs files before committing to a given plan here. Bob Fenner> Thank You Very Much, Benjamin

Sumpless Closed Loop Manifold Hi WWM Crew, <Glenn> I have a 75Gallon tank that I had drilled when I converted to DSB/Live rock filtration. I had only one drain installed and it cannot handle a more powerful pump return than 375 Gallons. This drains to a 20Gallon sump/refugium. The rest of the circulation is handled by 4 MaxiJet power heads suction cupped to the wall (All these pumps combined add up to 1000GPH). Unfortunately, the have been getting loose lately and creating snow storm in my tank. I'm fed up and want to try a manifold. But I cannot use the existing drain and I don't want to take the tank down to drill another hole. <Can, could go "over the top", edge of the aquarium...> The only option I can think of is an internal pump, like a Mag 12 or 18. How do I place this pump in the tank and still avoid my fish and sand getting sucked up. <Careful screening> Last year, I lost my Dragon Wrasse to an uncovered intake ,on a powerhead. Very disturbing site to see you favorite fish half in and out of a powerhead. (He was already sick though, I think that is why he was sucked in.) Thanks, Glenn <Do take a read through our site re manifolds, plumbing... a few options for you here... using pump/s outside the tank. Best. Bob Fenner>

Re: Sumpless Closed Loop Manifold, powerhead use 07/01/05 Bob, <Yes> Thanks for the reply. I've decided to go with an internal powerhead. After reading many FAQs and other forum threads, I've purchased a Tunze Stream. I went with the 6060, which cannot use a controller, to vary output. I'm amazed it can move more than 5 times the volume of water using less electricity than the Maxi Jet 1200's. <A very nice product> I've directed the pump to partially reflect off the front pane of my 75 aquarium. I'm hoping this will spread the flow in multiple directions. <Should> Should I run this pump 24/7 or power it off at night and run just a few maxi jets and the return pump at night? Thanks, Glenn <I'd leave all running continuously. Bob Fenner>

Overflows vs. Closed Loop 7/17/05 Good day, <And you> I really should be charged for all the questions I have been asking lately. so please feel free to let me know where I should deposit the money and how much :-) <We never turn down the cash!> At the moment I wish I never heard of "closed loops", because I am really battling with this. I'm setting up a new 150 Gallon reef tank and have really struggled a lot to sort out the water circulation. For my overflows I have 2 x 1.5inch bulkhead drains (inside diameter). From the sump I have a pump that sends about 1500gph into 2 x SCWD for the return. The overflows seem to handle this quite easily, with no problems so far. The problem I have is with the additional circulation. My original plan was to use an "over the top" configuration for a closed loop, where I don't have to use drilled holes. I'm finding the plumbing for the closed loop very difficult to do, the tank braces and "lips" makes life a little difficult with the "over the top" type setup, I'm finding it very hard to find the proper parts, ball valves etc. and I also have some space problems below my tank.. I'm very frustrated at the moment. <Seems so> So now I'm thinking of drilling an additional 2 x 1.5" holes to cater for the intake of the closed loop. At least this will eliminate the need for "over the top intakes". The one thing I would really like your opinion on is the following - The one place I do have a lot of space in is the "return chamber" in my sump. The total sump size is about 65 gallons, with the return chamber on its own taking up almost half of that. So the one option I was considering is - instead of using the 2 additional holes for a closed loop, rather add them to my current overflows and add the second pump to my sump. This way I will have 3000gph going through my sump/overflows with 2 return pumps and no need for the ball valves and other things I've been struggling with so much on the closed loop. I can split the overflow lines so that only part of the 3000gph goes through my refugium area and skimmer and the rest straight into my pump return chamber, so I'm not much worried about sending too much water through my refugium. Do you think the option of using more overflows with 2 strong return pumps instead of a closed loop for 3000gph be a bad idea? <Mmm, no> Should I rather bite the bullet and continue my struggles to get the closed loop going? <Up to you of course> Is 4 x 1.5" holes too much for a 150Gallon tank ? <Mmm, no> Ps. I will connect the second pump to another 2 x SCWD, so the actual flow rate will be a bit less than 3000gph. <Okay> Any advice will really be appreciated. <Perhaps a good idea to "step away" from this project for a while... Come on out to HI next month and go diving with me... all will seem clearer with a bit of a holiday away. Bob Fenner> Many Thanks Chris Re: Overflows vs. Closed Loop 7/17/05 Hi Bob, <Chris> Thanks for the reply. Diving with you sounds like a great idea, but unfortunately I'm thousands on miles away here in South Africa. <Ahh, our mate who has lived with us a dozen years is on a walk-about visiting in Swaziland... where he and his brother had a farm implement biz... till it was "nationalized"...> Have fun Chris <Mmm, do keep the "break" in mind... and re travel... "you get on a plane, you get off a plane"... Tis an exceedingly small planet my friend. Bob Fenner>

Will a closed loop for circulation really only work if you have the 7/26/05 water coming to the pump from either a hole in the back of the tank (below water line) or the bottom of the tank?  That is, am I wrong that a line that runs over the tank edge to the pump would not work, or work well, since a loss of power would break the siphon, for lack of a better word, to the intake of the pump.  Am I wrong here?   <Hi Jon, please see this link: http://melevsreef.com/closedloop.html  - Ali> Closed Loop W/Manifold Plumbing Design - 08/13/05 Hello crew, <<Evening>> I'm doing an open top 180G (6'x2'x2').  I want to do a CL with a manifold under the DSB.  I have the tank drilled for two 1.5" bulkheads for this CL.  As for pumps, I'm considering one of the Reeflo models (Dart, Barracuda or Hammerhead).  I know we can't get into exact head loss calc.s etc.  but hopefully you can help me based on your experience.  I want to be able to have SPS and any other high flow critter I'm interested in.   <<okie dokie>> While considering my CL question below, keep in mind that I want to try to get about 800-1000 gph from my sump return running through two Penductors (which supposedly should equate to approx. 3000-4000 gph they say although I'm a little skeptical of this number). <<As am I.  Have seen these (on a 180), just not convinced the flow is increased by this large a volume.>> So starting with a 1.5" bulkhead into the tank I could tee to a 1" loop or keep it 1.5".  I think I have plenty of room in the DSB to do a 1.5" manifold if it will be better. <<Not much (if any) advantage to keeping the 1 1/2" diameter here...would plumb 1" just to save on PVC costs/ease of handling if nothing else.>> My main question though is how many nozzles (size and diameter) to run off the loop.  They will have some LocLine to allow direction adjustment.  Assuming approx. 4' head loss a Dart would do about 2900 gph for 160 watts, a Barracuda would do about 3900 gph at 315 watts, and a Hammerhead would do about 5500 gph at about 370 watts. I don't want to have too few CL nozzles and have them act like jet streams, but I don't want to have a forest of nozzles sticking out of my sand either!  I appreciate any advice you can give me... <<Nozzle size/quantity will depend on the pump you choose.  You have some figuring/deciding to do here mate.  Decide how many nozzles you want...figure 350 gph per 1/2" nozzle and 550 gph per 3/4" nozzle...divide these figures in to the flow rates for the three pumps...whichever figure comes closest to the number of nozzles you want...wallah! Thanks, Randy <<Regards, EricR>> Get That Jet Stream - 08/13/05 Can you PLEASE correct my spelling of "get stream" to "jet stream"  in the last paragraph of my previous email if you put it on your FAQ pages?  LOL If you can that would be nice, if not, oh well, I'll just have to look like a goofball... -Thanks! Randy <<No worries my friend...took care of it.  Funny how the brain works/reads/disconnects sometimes, eh?  EricR>>

Closed Loop W/Manifold Plumbing Design II - 08/14/05 Thanks for the advice to assume 350 gph per 1/2" nozzle and 550 gph per 3/4" nozzle for my CL manifold.  Would you care to estimate a rough head loss number for a system like this?  Is 4ft reasonable or is there a rough number per nozzle I can assume? Thanks and have a great evening, Randy <<Aside from the actual vertical run, I would add a foot of head for each 90-degree elbow, a foot of head for every ten feet of horizontal run, and for good measure throw in another foot of head for the nozzles (combined)...yep, eats up flow rates in a hurry.  Do buy enough material to build a couple different configurations if necessary and test these for desired performance before making a permanent installation.  EricR>>

Manifold Recirculation Loop Made of Funny Pipe? - 12/06/2005 Hello crew ! <Hi there Pedro!> I have two questions: First one is fairly simple. I would like to know if the Manifold Loop can be made out of Funny Pipe or sprinkler plumbing. <I'm not familiar with Funny Pipe, but if it's of the same nature as sprinkler plumbing then I would be concerned about possible algaecides.> The second one more complicated: I have a Mag 7 as my return line pump for a 75 gallon reef tank ( not set up yet) and about 4 ft of head and the return line is a 3/4". I will keep the overflow the same 1". Do you think if I make the Manifold Loop to 1/2" reducing the return line, will give me the necessary flow?  <No. Making the loop 1/2" will restrict the amount that the pump can push into the loop, thus restricting flow before it even hits the outlets. Instead keep the 3/4", reduce the amount of outlets and use the outlets themselves as the reducing point (lock-lines are great for this). That said, the Mag 7 (@ 700 gph.) is on the short end of desired flow. To get at least 200 gph. from your outlets, you could only have about 3.> Or do I need a bigger return pump. <Would be better.> I will keep the overflow the same 1". IF you please can point me in the right direction it would be very well appreciated. <Since you're not set up yet, why not add a second drain to help accommodate more flow? Remember to plan for future intentions and not just the quickest way to get up and running (hard to, I know). A larger pump will serve you better, but don't over shoot your drain capacity.> Thank You,  Pedro Velasquez <Anytime. - Josh> 

Re: Closed Loop Manifold! - 12/13/2005 Thanks Josh, for the quick reply! <No problem. My wife had some things to look up, so I took the rest of the night off.> I got the CLM a bit more under control now thanks to you. <Glad to help, but I'll pass all credit to Mr. Calfo.> I just don't have very clear about the pumps having the MD 7 & MD 9 pumps  running together. <I only said this because you said you wanted the filtration separate from the CLM. In that case the MD7 gives you part of the flow, MD9 would make up the rest.> Wouldn't this be more complicated, and I guess they have to be connected in parallel right? <Much more complicated. Remember, in my first response I said you would only need one pump. If going with two, they would have to be separated entirely "a sump per pump", not parallel.> To make things easier and simple, I think I will buy a bigger  pump, like you said. <Good choice;)> But I just found out that the MD pumps are not recommended for saltwater external use, is this somewhat true? <Not really. You just have to look for this specific ability in the pump listed. Look at the Mag Drives here http://www.drsfostersmith.com/Product/NavResults.cfm?ref=3532&subref=AG&N=2004+113041 .> Because I would like to go external to lessen the heat. How about Sequence pumps?  Gen-X, Iwaki, Blue line or any other that's reliable and cost saving on electricity. <All would work as well. I didn't mean to get on a Mag Drive kick, that's just what you already had.> I could then use the MD 7 for the skimmer. Is this  a good idea or is this pump to much for a skimmer? <Again, depends on skimmer specs. Would be a big one though.> And to have this clear : Is this pump or pumps that we are talking about just for the filtration cycle or is this for the CLM? I want to have them separate with the CLM on a timer or wave controller. <I think you've missed one part. If done properly, the CLM will create all the random, turbulent flow you need. No need for the wave controller (saves money on electricity also). If you're worried about feeding time, just adjust the output with the ball valve. So, I mean one pump total. Return from sump is the CLM.> The filtration cycle is the standard corner overflow of 75 g: 1"  Overflow; 3/4" return but with an addition of  a "T" 2 outputs instead of just one. The CLM is 3/4" all the way with 6 "Ts"  and  1/2" outputs like you advised me to do with loc-line  nozzles and the input for the loop is 1" <I thought you decided to leave this at 3/4".> I think I need to buy 2 pumps, one for the filtration cycle and  one for the CLM. Please tell me what you think. And thanks again man.. <No sweat Pedro, the filtration question you have throws me though. The sump is "powered" via gravity so I don't understand where you feel the second pump is going to help. If I'm missing something in your meaning just shoot me another message. Hope I've cleared up the rest. - Josh>

Re: Closed Loop Manifold - 12/12/2005 Already took care of the return pipe issue. I'm going to leave it 3/4" and not mess with drilling. This is the main return from the sump to the  tank. I want to keep it separate from the Loop. What pump would you recommend! <Did you not receive my e-mail last night? As stated, I would go with the MD12 or MD18, add the extra outlets and limit output to desired flow with a ball valve. If running the MD7 as well, just get the MD9> I had the Mag 7 for this return, but I think is too small. <Correct, won't give adequate flow.> About the CLM: I'm not sure about the output size on the loop. The loop is 3/4" inside of the tank.  Should I have the "T's" with a  reduction to 1/2" or should I leave it 3/4"? <Reduce to 1/2. Find a way to taper this down as well (lock-lines or similar object).> It's going to have 6 outputs. 4  now, 2 later. <Why not six now?> I have no way of knowing at this moment how the flow is going  to be, because I don't have the pump yet. I would like advice on a pump for the CLM with 4 T's & 2 90 elbows and 2 three ways on two corners for a 75 gallon tank. I would have about 2 1/2 feet of head. <Try rereading Anthony's article on a closed loop manifold. I feel that aside from its effectiveness, the beauty is in the simplicity. - Josh>

Closed Loop Manifold - 12/11/2005 Hello guys from WWM! <Hi there Pedro! You've got Josh again.> Do you think it will make a lot of difference in flow if I make the return line for a 75g which is 3/4" to 1" to the top or beginning of the loop, then tee off for 3/4" pipe for the loop and outputs or just don't even bother of drilling the hole bigger for a 1" bulkhead and just do the 3/4" pipe all around. <I would just stick with the 3/4" all the way. Going from 1" into the tank and then dropping to 3/4" isn't going to be helpful.> Does the CLM need to be separate from the filtration cycle? <Nope. Just make it the return from your sump.> I  don't have anything setup yet, I'm in the planning mode. I don't have a pump for this right now, but will like to have a descent flow. <I thought you had the Mag 7.> Any recommendation will be appreciated. Need advice ( size and Brand )on an external pump that can be use as a return pump for main display and another for the Closed Loop Manifold. <You're fine with the Mag Drives, and the good news is you only need/want one pump to return water to the tank via your closed loop. Running two will be a problem as no two pumps will ever match each other precisely (you'd basically have to set up a sump per pump). Just size up to perhaps the MD12 or MD18 and control the output with a ball valve and more outlets.> I have a Mag 7, which the LFS sold me, but now I understand that's not enough. <If you're not running it yet, why not return it toward a bigger pump?> What can I use that mag 7 for? Is it too much to use on a skimmer? <Depends on the skimmer really. Find one that operates best with at least 700 gph and I don't see why not. Personally, I always have some crazy scheme for spare pumps. Cheapest route would be to try and take it back for a credit.>                                                           Thank you WWM. Pedro Velasquez. <Sure thing Padre...uh Pedro> Manifold plumbing 10/7/03 Anthony: I just finished reading your article on a manifold plumbing system. I think this is a great idea and plan on using it for my new 135g I will soon be setting up. However I am currently reworking my 55g and have some reservations. If I use a closed loop manifold, the pump needed would have to be fairly substantial.   <hmmm... not really. Or at least, no more than the output of three medium sized power heads to produce the same desired 10-20X tank turnover (500-100 GPH). This is a small external water pump indeed> The power consumption would be very high and the heat generated by a large pump in a small in sump substantial. <wow... you are way off the mark here my friend. A single external water pump will definitely run far cooler than the same muscle in submersible powerheads... and their power consumption is easily similar or less than the cumulative powerheads/Fluvals, etc. Look to Iwaki or Supreme for such reliable and efficient water pumps. The latter being the more affordable> I am not sure if it would be worth it. <its well worth it for all of the reasons above plus safety and aesthetics> I am wondering what you think of a hybrid between this and a  spray bar. <spray bars are antiquated and troublesome (tough to service and they diffuse the water too much)> 3/4" plumbing coming off the internal overflow on the left side and running across the back of the tank ending in the right corner. Outlets with LocLine fixtures evenly spaced , 2 or 3( your input required here), each preceded by a flow valve. Flow rate and direction would be controllable at each outlet. The black PVC and sch.80 fixtures I've located should be just about invisible. Do you foresee any problems, or anything I have overlooked?  Thanks as always, Ken <no need to re-invent the wheel here my friend... do stick to the plan ;) Kind regards, Anthony>

Manifold plumbing III 10/8/03 Thanks Anthony - I guess my question was not exactly clear. 55 gallon display with standard cabinet and 25 gallon sump = no room for an external pump. <understood... hence the recommendation for a Supreme (mag-drive) which is submersible> Manifold and plumbing = 9.5- 10' head pressure. A Mag 12 uses 110watts. wouldn't this generate a lot of heat for a tank this size? <again... no more (much less actually) than the 3-4 powerheads in the display that it would take to produce the same flow> I really wasn't going to use a spray bar per say but run the plumbing just across the back with 2-3 outlets, thus cutting down on the pump size. Your method or my mod.? Would a Mag 9.5 be sufficient? A little less wattage, a little less heat. Any other pumps you can recommend. <I honestly think you are overly concerned about the heat issue, mate. And what little is imparted can be easily dissipated by a cheap 9-watt muffin fan exhausting air from the surface of the aquarium (evaporative cooling easily rips off 4 degrees F)> Your friend in reef and reading( get that next book out) Ken <Thanks kindly :) Vol. 2 Reef Fishes is well underway... coming soon ;) Anthony>

Manifold plumbing IV 10/15/03 Understood. One last question and I promise never to bother you again (at least about manifolds!). <no worries, mate> The return from the sump is 3/4".Do you see any problems if I reduce it to 1/2" where it returns at the top of the tank. <not at all... there are advantages to both routes. You will get slightly better operation at head along with velocity at the expense (slight again) of some flow> The corner overflow on the AGA 55 is fairly small. It also has a Stockman standpipe. I simply cannot fit a tee to 3/4" pipe. <understood> How many outlets for a tank of this size? Forever grateful, Ken <6-10 would be nice... best regards, Anthony>

Questions about plumbing a "hard" water return line 9/20/04 I have read Mr. Calfo's article entitled "Plumbing a Water Return Manifold" and have built one.   <neato> Should I glue the pieces together, with the obvious exemptions being the tee's that need to swivel?   <Correct... glue the closed loop and its downward angled tees... but leave the nipples/stems and elbows/tees stuck into the outlet tees unglued> It is made out of 3/4'' pvc and was worried about pvc glue leeching chemicals into the tank once it is in use.   <no worries... is fine once cured> Also, I had a question about whether or not to make it one piece, a sort of "closed loop."   <Hmmm... you simply must if your tees are open and not regulated with valves on each one. The closed loop circle is critical for a manifold to build/maintain more equal pressure> Currently, it is in two pieces, to allow for the SCWD wavemaker to be able to blast each side independently, but I am wondering if I should make the manifold all one piece to make the flow more "balanced" overall.   <exactly correct> Also, about how many outlets should there be?   <depends on the needs of the inhabitants in the tank. I'd guess a tank this size will need/want about 4-6 here too or more> I know the article recommends 4 to 6, but currently, mine has 11 outlets fitted with 1/2'' Loc-Line adapters, to better direct the flow of each outflow.  The return pump is a Pond Master 12b that should be running at about 1000 gph after calculating head loss. <wow... this is staggeringly low flow. You will simply be disappointed how little flow 1000GPH is through 11 outlets... a literal trickle of less than 100 gph per outlet> The total water volume is about 75 gallons, if that helps.   <if this is a reef... I'd love to see at least 1500 gph of circulation in this loop. With 4-6 outlets... they would have reasonably good strength> I would like to create a suitable habitat for some easier to keep, colorful corals and other invertebrates (zoanthids, starburst polyps, a clam or two, perhaps a BTA, etc.) if at all possible.  Any suggestions for some "guinea-pig" species of the above mentioned things to see how well they do? <all fine... but please resist mixing any anemones (motile) in an unnatural mix with corals (sessile). Its a problem for most in the long term. We answer enough sad queries from problems in such mixes> I hope these questions make sense to you, let me know if anything needs clarification, I can also send pictures if you would like. Thank you very much for your time. Jeremy Weaver <best regards, Anthony> Plumbing 9/30/04 Dear The Gang at WWM, <howdy> Let me first start off by saying thanks for the amazing service that you and the WWM provide. Its a wonderful and invaluable resource of information. <thanks kindly! Please do tell a friend... hmmm, and recruit another volunteer to help us in the process <G>> I often find myself up till 2 or 3 in the morning trying to learn as much as I can about having a Reef Aquarium. I was reading your article by Anthony Calfo entitled Plumbing A Water Return Manifold goodbye powerheads!. I had a similar idea and was wondering if it would be more beneficial to make the manifold going around the back of the aquarium? <whatever is most convenient for your physical placement/layout of the aquarium> By just adding a second 90 at the top and have it run along the back of the aquarium, you can have two sets of return jets in the back corner of the tank, at three different levels in your aquarium. And the bottom of the manifold would just be straight pipe with 30 - 1/8 holes in it to aerate the substrate and behind the live rock. <the later being interesting but not necessary when you have adequate random turbulent water flow overall... and most importantly, have not made the mistake of building your reefscape against (leaning) any wall like so many folks do against the back of the tank (bad long term)> And would it be possible to incorporate a 30-gallon refugium in the system? <certainly> If so can you direct me in the right direction to where I can find out the best way of doing that? <we have an extensive refugium chapter in our latest book "Reef Invertebrates" by Calfo and Fenner... and have some great archived FAQs on refugia> Thank you so much for your assistance. Joe Othman <best regards! Anthony> Closed loop manifold Hey Gurus! <Stephan> I was wondering if you tell me where, in the back of the tank, where should I put a bulkhead intake for a closed loop powering a manifold? Top, bottom, middle? <Near the top usually... for a few reasons... to ensure more complete circulation, help with removing surface "scum", and sometimes very importantly, should the plumbing fail, to disallow the tank to drain completely> I am also worried about  the intake sucking precious animals like snails and such. The bulkhead is 1 1/2". Can I split it to two 1" instead? <You can... but this may not allow sufficient intake volume/flow... remember, the surface area of a circle formula? Pi R squared? How much larger is one 1 1/2" fitting than two 1"? Better to have two fittings joined or leading separately back though...> Can anything be rigged like some kind of strainer box covering the hole(s)? <Yes... these can be purchased or made... like lengths of capped pipe with cut perpendicular openings...> Thanks yet again Stephan <Welcome. Bob Fenner> Return spray bar Hi, <Hello> I've been reading the FAQs and searching setup info via google. However, I can't seem to find a good answer to my problem. I'm building a new tank - mainly planning to keep 2 or 3 fish, live rock, some soft corals, anemone and a clown fish.  The tank size is a room divider (visible both sides) with dimensions of 60 x 18 x 30 high. <Quite high/tall for the stated length... and likely height from the floor... if not too late, I encourage you to consider lowering this to 24 inches... much easier to get your arms into as well...> I've got a Dolphin 2100 plumbed from the sump to the tank using a 1" which is teed to two 3/4" hoses.  The pump is just under 6 ft below the top of the aquarium.  So, the problem is that the returns from the 3/4" hoses don't generate enough current around the tank with 3/4 inch 45 degree pvc outlets at the top of the tank (on opposite ends). <Good descriptions> Therefore, I connected the 3/4" into a couple of spray bars.  One of the spray bars is near the surface.  The other is actually plumbed from the opposite end towards the center to three vertical spray bars that spray from the bottom of the tank (I figured this was better since I plan to stock the tank sparingly and want the flow to be at the bottom and push water up towards the overflow.) Illustration:         3/4" PVC         I         I         I         I         I            l           l   1/2" PVC         ------------ l-----------l      1/2" PVC starts from  elbow The question I have is ... how do I know if I have too many holes or not enough? <Mmm, only from a practical application... i.e. trial and hopefully no/little error> I've drilled a bunch of omni-directional holes in the 1/2" PVC. (The 3/4" holes point towards the center of the tank.)  I don't know if I drilled too many or not enough. <Better to start with just a few, drill a few more later...>   I am trying to maximize the water flow into the tank while delivering the flow closer to where it's needed.  In calculating the area of the holes, it looks like I've drilled holes equivalent to 48% of the 1" hose cross sectional area (coming from the pump).  I'm hoping that this will help create good velocity out of the 3/32" holes. Thanks for the help! <You raise a few very good questions... common issues with plumbing, pumping of captive aquatic systems... most aquarium pumps are designed/engineered to produce "moderate" volumes at relatively "low" (compared with swimming pool pumps let's say) head/pressure... Going through turns, reductions (would be better to tee off, leave as much plumbing as the discharge diameter on your volute (1")), holes... There are, as you will likely agree, always "trade-offs" in life... and in this microcosm/problem... I would plan on possibly adding internal pump/s, powerheads (some are MUCH better than others... some input exists on WWM re) to bolster your circulation if you find/feel it deficient here. Bob Fenner>

Re: return spray bar Hi Bob, <Ken> Well, after doing some experimenting, I followed your suggestion and removed the fancy stuff and just terminated the returns at the top of the aquarium with 45 degree elbows on opposite sides of the tank.  I get a significantly higher amount of volume/flow through this instead of all of the fancy piping.  I think I learned the value of concentrating on flow instead of velocity. Thanks! Ken <Life is a series of compromises... the trade off in flow versus pressure appears to be a mini-lesson. Bob Fenner> - Plumbing a Closed Loop - Hi good guys. I am now plumbing a closed loop. The pump I am using is a Dolphin Amp Master 2100 and has a 1 1/2" inlet. I planning on drilling the back of the tank for the inlet near the top, and in the center.  My  dilemma is because of the sucking power of this pump can any animals get sucked on the screen on the wet side? <Certainly.> I thought maybe would make some sort of  Tee with 1 1/2" to two 1". I will add two screen on those and hope it wont be as much sucking power. I also would like to know if I can protect the area around those screens better so no animals gets caught? <There is an almost-flat intake screen made for 1.5" bulkheads which is designed to distribute the suction across a larger surface area and helps prevent animals from getting injured. I would go to great lengths to seek one of these out.> Perhaps I can build some kind of box with holes around the intakes? <Or surround with live rock.> Help! Thanks for all the great advise Sincerely Stephan <Cheers, J -- >

Tank move, lighting choices and closed loops 2/3/05 First off, I'm amazed at the info I've learned from streaming through all these pages. Thank you ahead of time again. <Glad you have benefited!> I am moving to Florida and must break my 180g down. Possibly several months before I will be able to restart. Unfortunately will not be able to save LR but can reseed it.  <If you can't save the live rock, please sell it or give it away. Once it dries, I would not suggest trying to re-use it. It will be full of organic matter from all of the bacteria and tiny critters that died upon drying.> Current FOWLR, next set-up to be reef (some SPS, Mostly LPS, 1 xenia, 1 clam). Tank is 72x24x24. After the sandbed, the water column will be 20". Currently, I am looking at the Coralife Aqualight Pro HQI 3x150W DE HQI, 4x96 Actinic. Obviously, I will replace MH lamps w/Aqualine bulbs. Will this offer enough light if specimens placed at appropriate heights? Any good or bad remarks\reviews for this product? Or should I purchase another manufacturer? <My experience with Coralife lighting products is mixed. If you are going to replace the lamps with Aqualine lamps anyway, why not look at AquaMedic fixtures? They have a better reputation for quality and the lamps you want will be included in the (admittedly much higher) price. Aquamedic produces fixtures with PC's or T-5's.> I plan on adding large refugium and closed-loop water flow to hit around 20x turnover, but having some problems with schematics currently, any thoughts? I want to plan ahead.  <Sounds good, but I am not sure what to suggest without a little more to go on. From the cuff... Be sure that the inlets to your closed loop diffuse the suction effectively (no sucking up fishies!) and use as few T's and elbows as possible.> Any thoughts on placing my skimmer AquaC EV240 outside my sump (changing water levels in sump tend to really play havoc-awesome skimmer though)?  <You could place it outside of the sump, or simply elevate it so that the outlet will always be higher than the water level in the sump.> You have always been so helpful. I print out a ream of FAQ and just read and read, then reverse paper and print on other side-another 2 inch stack of FAQ. Wife thinks I'm crazy. Thanks <Glad to help! All of our spouses think we're crazy! Best Regards. AdamC.>

Perimeter, Closed Loop Manifold for Water 2/7/05 Forgive me if you have answered this question, but I couldn't find it in a Google search. I would like to add a return manifold to my existing system for additional circulation. The 1" drain from my internal overflow will not support any more flow... <This is common among under-sized/drilled, so-called "reef-ready" tanks. No worries though... run a safe and modest flow through this overflow for your sump, but drive your manifold with a submersible pump in the display such as a Mag drive... or an external pump tapped into the display tank wall. This will allow you to drive the manifold with good strong flow> ...so I would like to add a external pump that pulls water directly from the display tank, and not use sump water. <BINGO!> However I cannot drill my tank, and I would rather not have an external overflow.  <The heat is a small issue in most tanks for submersible Mag drives... do consider since you can't drill> And for aesthetic and heat generation reasons, I would rather not have the pump inside the display tank.  <hmmm... OK> Would the design illustrated in the attached .jpg work?  <Not safely> If a pump specifies that is not self-priming, how would I initially get the water through the intake PVC to the pump?  <By no safe/reliable means I know of... you will burn out this pump eventually> Would it stay primed, if the water level in the tank never dropped below the PVC intake?  <Most of the time I suspect> Are there other issues I am not thinking of?  <Yes... principally air bubbles that accumulate in the display that can interrupt this prime> I have also thought of running the intake PVC down into my internal overflow housing so it is not visible when viewing the aquarium.  <Impossible... the air/turbulence> What kind of issues would this cause, if any? <As per above> Thanks for any help you can give. <Without a submersible pump or drilling the tank, you are beat like the proverbial red-headed step-child. Best of luck, Anthony>

Closed Loop Configuration Hey there- <Good evening- Scott F. here tonight!> My little giant pump on my 125 is rated at about 1300 gallons per hour. I currently have just two outlets with ball and socket flex tubing. Would you recommend that I just place a couple powerheads in the tank or possibly use a mag drive pump plumbed from the 3/4" hole in the overflow box (normally used for return from sump) for a closed loop and plumb the main return from the sump behind and over the tank instead of up through the overflow box.  The closed loop return lines would also run behind and then into the tank.  The only problem is that I don't know if the all glass overflows can handle much more flow through them unless the slits at the top of boxes were widened.  The other option would be to plumb an intake in front of the overflow box and then down through the box as Richard Durso has described.  I hope all of this isn't to confusing.  Thanks for your help. Josh <Well, Josh-you do have a variety of options for the closed loop. The most common configurations that I have seen simply have intakes in  bulkhead fittings installed into the side of the tank, never having anything to do with the overflow box(es). Richard Durso's idea is good, too- he has a nice idea and makes one heck of a good standpipe, too! I guess my recommendation would be to do whichever configuration you are most comfortable with. And, do check with the people at All Glass regarding the flow rates that their overflows can handle...Sorry I couldn't be more specific-like I said, so many ways to accomplish the same thing! Good luck Scott F.>

Overflow- undersized as usual Quick question I keep forgetting to ask.  I have 2 1.5" bulkheads drilled into the back corners of my 75gallon tank. I am wanting to surface skim by putting 90 degree elbow attached to the bulkhead in the tank. (also help in the event of power failure/siphon) But... I can not get rid of the water swirling/sucking into the elbow.  Looks like a tornado sucking into the 90 elbow and in sounds terrible.  Any suggestion on what I can try? Thanks Bryan <this is a common problem bud... the overflows are simply too small in size or number. A common problem. What is happening is that your "oversized pump" (really not too big... just too much for the lack of holes/size) is pumping faster than they can gravity overflow and a siphon is being created (the sucking noise). Put a gate valve on the outflow of the pump and slowly restrict its volume returned topside until the noise stops. How ironic... you'll have to restrict the pump and then add power heads in the main tank to compensate for the lack of water flow (adding heat, electricity, eyesore, etc). Bummer dude... but a common problem from bad advice and poor overflow design by the manufacturers of tanks. Best regards, Anthony>

Closed Loop 7/22/03 Okay, now that I understand the principles involved, I think I want to make a closed loop work. I figure I'll need to run a siphon over the edge (can hide it in the rocks) to supply the pump as the two 3/4" bulkheads will not handle the extra flow necessary which I figure is about 2,000GPH (shooting for 3,200GPH total). <I do not/will not recommend an over the tank siphon for any reason/application. They are archaic and prone to fail in time. In this case... at the expense of burning out your pump of it should lose prime. Closed loops as stated before are tapped into the tank. Literally tapped - two drilled holes... shut-offs coming off that... then quick disconnects... then the pump in between. All for convenient pump cleaning or replacement without draining the tank later. Do visit the message boards for perspective from many others that have tried this. A common strategy with SPS keepers> If I want the siphon to handle the total flow, what size do I need? 1.5"? 2"? What kind of strainer should I have on the business end? <the pump has an inlet and outlet size/tolerance. Simply follow the pump/mfg specs. And I prefer a coarse foam block on the intake if it will be serviced regularly... better/safer would be a sturdy filter cage like we use on pond pumps for leaf litter> One thing I have going for me is that I can run a manifold above the perimeter of the tank just about any way I want to. I know there are unlimited options in tweaking this sort of thing but where should I start? three 1" outlets? Four or five 3/4" outlets? <depends on the pump again... my friend. You are putting the cart before the horse. That said... 6 outlets on a four foot tank are in the ball park with 3/4 or 1" pipe> Should I bother with Sea-Swirls? <they are fantastic... just pricey> My tank is 69X24X24 so I estimate the net volume (minus two corner overflows) at 164 gallons. Thanks for your patience and also your books which I found after I have made a couple of mistakes but in time to help me correct them. George <slow down and enjoy the journey, bud :) its a beautiful hobby. I would strongly suggest you take some road trips to regional aquarium societies and stores to spy their aquariums and plumbing to put this all in perspective. E-mail can only do so much. Best regards, Anthony>

- Plumbing a Closed Loop - Hi again.  I have (another) question for you all.  This is a quick one, I promise.  I'm finally ready to install a closed loop on my 55 gallon tank (thanks for the advice on this a few months back!).  My question is: I have a quiet one 4000 pump which has a 1" outlet that will be feeding the closed loop, coming from a small tank below main tank.  Should I keep it 1" PVC for the loop or should I reduce it down to 3/4" PVC and if so, does it matter where I put the reducer pipe? <I'd go ahead and reduce it down - near the pump.> The pump should be pumping about 750-800gph after factoring in the 3' head going into the tank. <Perhaps a little less with the reduction in the output. Should still be plenty for a 55.> I will be putting about (any advice - more or less T's?) 6 movable T's spaced through out the perimeter of the tank - except for the back left wall.  This is where the overflow box and hang on skimmer is so no pipe can go there...  What's your take on this? <Sounds fine to me.> I've actually bought the 3/4" pipe etc. but now I'm not sure if I should be reducing it or not? <Would be best to maintain the same diameter as output on the pump throughout, but 1" pipe will dominate the top of your tank if you are building a manifold.> Hoping to get the most flow possible so I can get rid of powerheads... <Mmm... can understand the aesthetics motivations.> Thanks once again.  You all are great and your advice is well appreciated. Jan <Cheers, J -- >

- Closed Loop Plumbing - Hello WWMCrew! I am having a 180 AGA Reef Ready tank custom drilled for a closed loop. I had initially though that four 2inch holes placed at different levels on the back glass along with two 1inch holes placed about six inches up from the bottom of the tank (also on back glass) would allow for good flow throughout the tank. The arrangement would be as follows - two of the 2inch connected to the intake and one of the 1inch connected to the output of a little giant 4mdqx-sc and then the other three connected in a similar fashion on their own little giant 4mdqx-sc pump. <Hmm... a little scary. I wouldn't feed anything from drains below the water line. If a pump or plumbing fails, your tank will drain until it can't... and that would be a huge mess. I would feed your closed loop from one of the stock overflows.> Additionally, I am considering plumbing the return holes in such a fashion that I can split the return several ways and "snake the return lines to different positions in the reef stack. I thought about cycling the pumps off every four hours to try to generate a more "random" flow - but I'm concerned that this will not be good for the life of the pump. <Your thinking is correct, you will destroy the pumps.> I'm also concerned about the size and number of holes I am contemplating putting into the back glass. All that said would I be better off to reduce the number of holes by half and add two of the Tunze Turbelle pumps positioned so that they point at each other? <That's what I would suggest.> Attached is the initial placement jpeg... Thanks so much! Lisa <Cheers, J -- >

- Re: Closed Loop Plumbing - Truly confused now! I have read that using the overflows are bad practice for closed loops because of limited real estate for holes in the bottom - especially on the AGA tanks --- and depending on how they are plumbed, they can exceed the capacity of the of the overflow. <That's what valves are for.> I have seen where people drill holes in the side of the over flows - but that puts you in the same situation of the tank draining if a pump fails... <Actually not... the overflow contains a limited amount of water. If there were a power failure, all that would drain would be the water in the overflow box, and not the contents of the tank.> Not sure how to proceed at this point. <What happened to the two Tunze Stream pumps?> At any rate I have re-thought my original design and am going to limit the holes to four; two midway up the back glass for pump input and two about 6 inches up the back glass for return and try using SCWD's internally on the returns to vary the flow throughout the reef. I have read that they can be used internally or externally - but I don't have any experience with these devices so any input on SCWD's used in an internal application would be great... <Will work fine internally, although you may find that you need to clamp the hoses on the SCWD is the water pressure is too high.> BTW - hole sizes are also changed (gone down) from the original to 1 1/2 inch for the pump input and 3/4 inch for the pump return! This design modification will also allow me to not power cycle the pumps off every 4 hours! <Ahh good.> Thanks in advance! --- Lisa <Cheers, J -- >

Many Manifold Questions... Dear Crew, <Scott F. your Crew member today> Reading through your plumbing articles and FAQs has inspired me to redo my reef plumbing.  I especially love the closed loop manifold and am thinking I need to mosey on down to the local hardware store to start picking up some PVC. <Great idea, fun to plan and build, and really useful!> I have a couple of questions before I mosey, though. <Sure..> I have an in-sump Mag 9.5 whose return line is upgraded to a 1" flex hose.  The return line travels five feet to the top of the tank and will connect to a 3/4" pvc closed loop manifold.   Question one:  Wouldn't 8-45 degree angles in each corner rather than four 90 degree angles help to prevent the water return pressure from reducing in the manifold? <Good question, and I suppose the answer really depends on the outlets' distance from the pump. On the other hand, you want a fairly sizeable number of outlets for maximum water dispersion/circulation, so it may be better to go with the greater number of outlets at lower pressure...You may have to experiment a bit before the manifold is installed...> Question two:  I plan on having six outlet Tee's, one in each corner between the 45 degree angles, one in the center of each long side.  The tank is 36"LX18"X18".  What I haven't been able to determine searching through the plumbing/manifold FAQs is what size should the flexi ball socket tubing for the outlets be, 3/4" or 1/2".  I'd like to get the best flow possible coming out of the outlets-not too weak, not too restricted. <Agreed...If it were me, I'd go for the 3/4"> Thanks again for all the help you folks have given me and fellow aquarists.  Chris   <Always a pleasure! Good luck and have fun! Regards, Scott F>

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