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FAQs about Circulation Designs for Marine Systems

Related Articles: Circulation, Inexpensive Wavemaker Impressions, by Steven Pro, Plumbing Marine Systems, Holes & Drilling, Plumbing Return Manifolds, Aeration, Water Flow, How Much is Enough, Powerhead Impressions by Steven Pro, Marine System ComponentsRefugiums, Central FiltrationFlow-through Live-holding Systems, Refugiums, Business Set-Up

Related FAQs: Marine Circulation 1, Marine Circulation 2, Marine Circulation 3, Marine Circulation 4, Marine Circulation 5, Marine Circulation 6, Marine Circulation 7, Marine Circulation 8, Marine Circulation 9, & FAQs on Circulation: Rationale, Pumps, Plumbing, What's About the Right Amount, Troubleshooting/Repair, & AerationPumps, PlumbingMake Up Water Systems, SumpsRefugiumsGear Selection for Circulation, Pump ProblemsSurge Devices

How To:
Try all out on paper first... get considerable opinions re pumping, plumbing, what's available, useful... what it will cost to run...

Airlifts? 4/23/08
Good morning! I am doing research of airlifts for water circulation in large 4'x18'x2'deep tanks for coral propagation.
<Oh, Dick Perrin uses this water-movement mechanism in his facility... Tropicorium >
I have scoured the internet and WWM and have not found any places that show the functionality of a large scale airlift system.
<Mmm, there's a bunch... in the engineering end for destratification systems for lakes, ponds... but you'll have to make a trip to a large (college) library>
I know that many people have used them on systems similar to this. Thank you for your time.
Andrew Lawing
<Maybe a call or email to Aquatic Ecosystems... or Argent Chemicals (the first for general reference, glass airstones... the second for their large collection of in-print materials. Bob Fenner>

Flow Question... design, pump sel.  01/18/2008
Hey guys,
<<Hello, Andrew here>>
Just wanted to bounce something off of ya, I have done a tremendous amount of research on the matter but wanted a second SANE opinion before I take the plunge. I have two 300 gal Rubbermaids plumbed in my system (yep retail), flow comes from the sump via a Sequence Hammerhead. In each 300 I have 2 Tunze 6100 streams, but recently I noticed detritus build up in the bottom. I am trying to make this as bullet proof as I can, so here is the question, I know some commercial facilities use airlift tubes, however, I think in my situation I am best to roll with closed loops, specifically powered by a Sequence Dart or Hammerhead (possibly even eliminate the streams).
<<This is the best option yes>>
At this point Im thinking I mind as well spring for the Hammerhead and be sure I have more than enough pump, as from what I have read, sps tanks should turn over as much as possible, ideally 60x. Just looking for a sanity check
<<Sanity check granted. Your plan will be fine. SPS do require a very fast amount of flow, some even go a lot higher than your stated 60 x water circulation. Good luck and I hope it does well>>
Thanks, Tom
<<Thanks for the questions, A Nixon>>

Reef Circulation Question 12/28/07
Good Day Crew,
<Hello Eric.>
(I'm sorry if a similar question came through just now, but my email system "crashed" right before the email went off and I'm not sure if you got it..)
Thank you (to everyone) for a truly beneficial service. I read almost every night, sometimes for hours at a time. My reef tank would not be even close to what it is now without this site. (It’s now my ‘Healthy Obsession”). I would also have no idea what an Aqua C Remora is (Excellent Product by the way).
<Very nice to hear of your success.>
My question is as follows: I am looking to improve my circulation. I currently have a 55 gallon (standard 4ft length) Reef which consists mostly of Polyps and moderate flow requiring Corals.
I have three Powerheads, the skimmer, and a Whisper 60 Filter (changed and cleaned often to prevent build up).
-My first PH is a MaxiJet 1200 which is located on the left side wall, facing center.
-My second PH is an AquaClear 70, located on the right side wall, also facing center.
-The third is a MaxiJet 600 with a rotating deflector attachment. This is facing “front and center”
The problem with this setup is that the MJ 1200 vastly overpowers the other two, and the stream is such that it creates a high level of Laminar flow. (The AC 70 is old, and although it has been cleaned thoroughly, is very weak, only producing about ¼ of what it’s supposed to.
<OK>
I have a few options. The first is that I could ditch the powerheads (most anyway) and add an Ocean Runner PH2500 (650 gph) which I have that’s not being used, and attach that to a PVC pipe system, where I could run it along the top of the aquarium. I could drill/etc. holes in the pipe so it would spray downward. I could add a few other powerheads for supplemental flow, but this should be fine, correct?
<This could work, by the time you add the plumbing to the pump you will likely have less flow than what is currently in your tank.>
I figure if you don’t include the skimmer and filter, it’s still over 10x per hour of circulation.
<It is surprising how much the plumbing will reduce the flow of the pump, perhaps even in half with a spray bar.>
Another option would be to keep the existing powerheads except for the AC 70 and replace that with another MJ 1200, and put these toward the top of the aquarium.
<Yes.>
Out of those two, which is the best?
<For my time and money, adding another MJ1200 is what I would do.>
Also, if you have any suggestion that I’m not thinking of, I would love to hear it.
I have been reading a ton, and discussing it with fellow reef enthusiasts who seem to think the first idea is better than the second.
<More and more reefers are getting away from powerheads and going to closed loops. If you don’t mind the look of the powerheads they give you a more adjustable flow pattern and are cheaper to run. It is a matter of personal preference. I own the particular Ocean Runner pump you have and love it. But, the two MJ1200’s will definitely outflow the pump.>
Once again,
Thank you for the help.
Eric
<Welcome, I hope this helps you decide, Scott V.>

Flow... Reef circ.    9/4/07
I am running a 120g 48x24x24 reef tank, with about 150lbs of Live Rock. I am looking at 3 maxi-get 1200 powerheads which have 295gph each, and a controller for it, with 2 rotating in opposites and a third on a separate timer. Along with my 800gph from my little giant should that be enough flow?
<It totally depends on the arrangement of the tank and what kinds of coral you want to keep. It's probably sufficient for corals that need less flow, but probably not enough for Acropora types. But again, it will depend on the arrangement of the pumps and the rock. Keep the live rock off of the walls of the tank to maximize flow (that will help).
Best,
Sara M.>

Re: Flow, reef, circ.   9/5/07
Yes the rock is positioned at least 5-6" away from the glass at all times.
<excellent>
The complication in the tank is that there are two overflows ( not corner placed) so there is sort of a challenge to stop dead space between the two overflows and the rock, since the effective distance from the outer edge of the overflow to the rock at times is small around 2".
I picked up a Tunze 1200gph powerhead, I like the output it is very strong but very broad, so it makes alot of water movement without putting any super high movement areas in front of it.
<Ah yes, these are great. I also have one and I absolutely love it.>
Would two of those Tunze 1200gph powerhead seem reasonable for the tank,
they would be aimed from the two upper back corners down towards the center of the front of the tank where they would collide and create turbulence...
<This sounds like a good idea to me. Another nice thing about the Tunzes is that the flow is so bulky that you don't get as much turbulence when you point them at the same spot. But turbulence is ok (actually preferred for some corals) so long as it doesn't constantly cause sand storms.>
with possibly one or two of my old 250gph powerheads hidden in between the two overflows to prevent a dead space in that area?
<Sounds like a plan... when it comes to water flow, more is almost always better than less. Seriously, short of putting a fire hose in your tank, it would be quite difficult to have too much flow.>
Thanks again for your continued patience with me
<no bother at all :) >
Josh
<Best,
Sara M.>

New Custom 120g...Wanting A “Quiet” 2400gph Turnover Rate! – 08/17/07
Wet web media crew,
<<Hello Matt>>
I have been reading nonstop for a couple days (there is a staggering amount of data on your website)
<<Indeed>>
and am trying to get the best configuration. I know I want the 48” wide tank; most likely 24” x 24” for the other two dimensions.
<<A standard 120-gallon tank then>>
The Lee Mar guys are the ones making the tank. The standard 48x24x24 has one 2” drilled drain then two 1 ½” return holes in the back center overflow.
<<Better than most...>>
I do not think this is adequate so I must have them customize the tank. (Any suggestions here would be great, I want to get it right the first time instead of regretting a choice and be stuck with it.)
<<Mmm, well...I need to know what your “goals” are with this system to be able to afford much help>>
I want to make sure that I have a big enough drain that it will be quiet and able to easily handle 2400gph, then add a second one as a backup and to supplement draining.
<<Ah, okay...then I would have “three more” of the 2” drains installed. This will give you about 4800gph “maximum” capacity. This is a bout half what some folks/most drain calculators will tell you...but is a more practical number/expectation in my opinion. Even though four 2” drains will make your goal of 2400gph quieter/easier to plumb, processing this much flow through a sump just below the display will be anything but “quiet”>>
I think both drains could be in same overflow box.
<<If you are considering a maximum of only two drains your goal of 2400gph of quiet flow “may” still be attainable, but will require much tweaking/tuning to achieve. Perhaps you should consider a closed-loop to boost the water flow within the display and utilize a much smaller “return” pump>>
If I have read correctly a 2” bulkhead would be the appropriate size (making the drill holes ~3”).
<<Not in my opinion...as stated earlier, I would plan on about 1200gph per 2” drain>>
Would there be any advantage to drilling the holes in the back glass (still in the overflow) instead, or in addition to, the bottom glass?
<<This is my preference...if only to limit the amount of water lost should a bulkhead fail>>
Are my dimensions correct for drain sizes?
<<Do consider my statements re>>
With drains this size, would a stand pipe, such as the infamous Durso standpipe still be required to decrease noise.
<<Likely, yes...and would need to be constructed of pipe of the same diameter as the drains to prevent loss of flow capacity>>
Not sure about the whole closed-loop system.
<<Is the “better” option here I think...or some Tunze Stream pumps>>
Given a big enough sump, any problem with that much flow through a sump?
<<I think you will be surprised at how much noise 2400gph of water volume dumping in to a sump can make. Even if the sump is large (100+ gallons), it will be a challenge to quiet the noise and control the turbulence/bubbles>>
Is there any disadvantage to having 3-4 extra holes (in each of the corners of the tank) in the bottom to have available for return flow and cap any not in use?
<<Of course (NOW is the time to drill these)...and I would not “cap” these but rather utilize them without increasing the flow rate to help reduce noise/plumbing issues. The more drains available...means fewer gph per drain...means fewer hassles all around>>
I would like to use as few powerheads as possible for adequate flow and still be able to keep SPS.
<<Can be done, though I find the Tunze Stream pumps to be very quiet, very efficient, very flexible in their application, and quite worth the “intrusion”>>
I appreciate your time and will be purchasing the tank in the next month. If you have any suggestions or ideas for this tank, please feel free to add any suggestions.
<<I suggest you chat with/seek other’s opinions re pumping this much water through your sump...research other options and base a decision on your own good judgment>>
Thank you,
Matt
<<Happy to assist. EricR>>

Re: New Custom 120g...Wanting A Quiet 2400gph Turnover Rate! – 08/22/07
Eric or other expert,
<<Just Eric here…>>
I have revised my plan to incorporate the response from Eric into my tank. Attached is a schematic of the tank-in-progress.
<<I see it>>
Would it be better to 'T' the two corner holes for the intake of the closed-loop then 'T' the two middle of the tank returns for the return then just use one bigger pump?
<<With the configuration shown (if I understand/interpret it correctly) I think you will have better control/efficiency utilizing a separate pump for each as you show. Though I suggest you swap the ball-valves for “gate-valves” (more control/finesse), and move them to the “output” side of the pumps (you don’t want to “starve” the input side of the pump)…and I would even consider up-sizing the pumps to a Mag-9.5 to allow for future loss of flow as the bio-film builds up in the inside of the plumbing>>
The current plan is to use a 30-40 gallon sump with a Mag 18 return, theoretically giving around 1200 gph through the sump.
<<If utilizing the two 2” drains in the diagram to feed the sump…excellent>>
The refugium will be a separate 20 gallon tank that utilizes a powerhead to get water into the refugium and is gravity fed back into the sump.
<<This will work fine…though you could add a tee off one of the drains to feed the refugium as an alternative (regulated with a valve)>>
Do you see any obvious, or not so obvious, problems to this design?
<<Not thus far>>
What is your opinion of the devices that rotate flow between returns (i.e. Ocean Motion)?
<<I haven’t used these myself but have a friend in the trade who uses them extensively with his customer installations. The devices seem to be well made and he “swears by them.” I think they are worth your further investigation if you are interested in regulating flow thus>>
Thank you for your continued assistance.
Matt Jenkins
<<Always happy to help. Eric Russell>>

R2: New Custom 120g...Wanting A Quiet 2400gph Turnover Rate! – 08/25/07
Eric,
Hey Matt!>>
You are an excellent resource in learning and implementing proper reef design.
<<Thank you>>
I thank you for your help.
<<Is my pleasure>>
The purpose of having a ball/gate valve before and after the pumps of the closed loop would be to allow me to take the pump out for cleaning and maintenance without a bunch of water flowing out.
<<Indeed…and agreed this will be necessary if you are not utilizing some kind of overflow box that would limit the “drain-down” with the closed-loop, in which case just a “Union” fitting before the pump would still allowing disconnection but with less restriction than a valve>>
Is there a better way to close both sides in the event I need to work on the closed-loop?
<<Mmm…not if the intake for the loop is positioned such that the transient water volume would overflow the sump>>
Would it be beneficial to increase the closed-loop plumbing in order to accommodate the gate-valves (while leaving the bulkheads 1")?
<<Ah yes! As you may have noticed, the valves have smaller inside diameters than the piping they are intended to match… And if you don’t want to upsize all the plumbing you could just “bush-up” the fittings at the valves (a 1.5” valve will come close to giving you a 1” inside diameter)>>
Again, thank you,
Matt Jenkins
<<Any time… Eric Russell>>

How to Protect an Anemone from a Powerhead – 8/19/07
Hello!
<Hello, Brenda here>
I have two Hydor Koralia Powerheads in my tank and had a gorgeous anemone that is no longer with us as I came home one night and he got caught up in the powerhead.
<Ouch!>
Needless to say, it was a VERY SAD night. I definitely want to get another anemone and today I wrapped the powerhead with some fiberglass screen. However, I noticed that the flow of water has greatly diminished. My question is do you have any suggestions as to how I can remedy this? Is there some other tactic to prevent this from happening again without buying another powerhead?
<Not without decreasing your flow.>
If I do need to buy another powerhead, what would you recommend?
<First, I don’t recommend the use of powerheads with anemones. The Hydor Koralia is a difficult powerhead to cover. A powerhead that comes with a pre-filter sponge would help, but is not 100% safe. I have seen an anemone loose some tentacles when it got too close to the sponge. Many have been successful using needle point canvas around their intakes. You can cut this to any shape you want, and tie the sections together with fishing line. Again, this method is not 100% safe. It is important that the canvas is not directly located on the intake, but kept a few inches away. If kept too close, the anemone can still get pulled through the canvas. There is more information with pictures located here. http://www.karensroseanemones.com/coverpowerheads.htm Hopefully, someday we will see a powerhead manufactured that is 100% safe for our anemones.>
Thank you! You all are phenomenal!!!
<You’re Welcome! I hope this helps! Brenda>

Noisy Powerheads, Wavemakers  3-13-07
Dear Crew,
<Hi Guys.>
As always, thanks for your help!
<Of course.>
We have a 72G reef tank (see photo).
<Neat.>
For circulation we are running 3 MaxiJet 1200 power heads linked to a Red Sea Wavemaster Pro.  This set up creates lots of turbulent circulation.
<Yes.>
However, we notice that the power heads make a noise when they turn on as part of the Wavemaster timing sequence.  We hear this and the fish jump.
<Mmm...yes, the constant stopping and starting of the impeller, especially over time can lead to diminished efficiency.  Furthermore when is the last time the pumps were taken out and cleaned?>
Is this sound normal?
<If they are old or in need of a cleaning yes. I would take them out and disassemble the intake grate...check it for debris as well as clean the impeller area. If there is calcareous algae build up, remove it.>
Is this bad for the fish?
<If the noise is sufficient enough to lead to stress, it's not a good thing.>
Is there a better way to achieve circulation?
<Personally I like closed loop systems better as they can be designed to be more aesthetically appealing and not impart heat into the display area.>
Thanks in advance for your help.
<Anytime.>
Jan & Ellen
<AJ.>

Pump & Stocking Advice; skimmer op., reef stkg., circ., spray-on foam inside backgrd.s    - 02/21/07
Dear Crew,
<Scott>
I sent the basics of this email on Saturday and didn't receive a reply, so I thought I'd send it again.  If you received it previously, I apologize.
   <I don't recall seeing this. Thanks for re-sending>
  Thanks again for this forum.  I can’t tell you how invaluable your advice has been.  You offer great advice that saves hobbyists a lot of grief and heartache, not to mention $.  Unfortunately I got overly excited when I saw what I thought was a great sump/refugium.  I ordered it prior to measuring it and prior to receiving my Euro Reef RS-180, which I can’t wait to set up.  The front compartment is too small for the skimmer.  I am going to attempt to modify it, however, if I can’t I may be forced to house the skimmer in the final compartment which is where I housed it when my 150 gallon reef was set up 8 years ago but times have certainly changed since then.
<Not that big of a deal...>
How much of an added benefit due you feel there is to housing the skimmer in the 1st compartment versus with the return?
<A few (single digit) percent>
  I sincerely appreciate your passion and responsiveness.  I’m establishing a 180 gallon reef which will house Acropora, Galaxea (I need to provide room for growth and to account for their
“stingers”),
<Oh yes>
a torch, a yellow Sarco, zoos, and another group of soft corals such as polyps or Ricordea.  I’ll also have Tridacna clams.
  My fish choices are:
Pr of BT Triggerfish (or Sargassum Triggers)
(1) Sohal Tang (my preference, but also considering Powder Blue, Palette, or Purple)
<The Sohal will be "king" here if placed>
(1) 6-Line Wrasse
Small school of Chrysiptera (Flavipinnis, Hemicyanea, Caeruleolineata, Cymatilis, or Chromis (Scotti or Viridis)...as these seem to be among the least aggressive
(1)Yellow Assessor
(1) Pseudochromis Fridmani
(1) Oblique-lined Dottyback (Cypho Purpurascens)
Pr of Clowns (Undecided on type)
(1) Flame Angel (Unsure if this is a good choice due to the clams)
<Likely okay in a setting of this size, type>
(2) Shrimp Gobies (preferably Amblyeleotris Yanoi or Stonogobiops Yasha, but welcome recommendations based on the other inhabitants) with commensurate shrimp
<Mmm, your triggers may consume the shrimp...  best to place these ahead of the Balistids>
  (1) Mandarin (last fish WELL after the tank is established)
<Mmm, may likely starve... hopefully can be moved to the refugium...>
I will be including a school of either Scott's Fairy Wrasses (1 male – 3/4 females) or school of Anthias (preferably Pseudanthias Bimaculatus, Fasciatus, Rubrizonatus, or Squamipinnis,
….recommendations?  
<Any of these, or even two species would work... one male...>
What are your thoughts/concerns about including both the Anthias and the harem of the Scott’s?
<Can be done in a six foot long system...>
If I were to go that route, what fish, if any, would you eliminate?  
<Mmm, none stick out from what is listed>
The last thing I want to do is overcrowd the tank.  If I go with the Anthias, I will still be adding a male Scott's.  I would appreciate your recommendations.
The tank details are:
180 gallon acrylic w/ 60 gallon sump w/refugium
Euro Reef RS-180 Skimmer
I am contemplating adding a Calcium Reactor at a later date.
<A worthwhile piece of gear>
  3 MH (I don’t remember the wattage… still have the ballasts from a 150 reef I ran 8 years ago) and 2 Actinics (aesthetics)
<I see>  
  I haven't decided on the pump yet.  I’m leaning towards an Iwaki 70RLT (1500 gph @ 4' head) or 100RLT 2000 gph @ 4' head), although I am reconsidering the Dolphin line as well.  I need to determine what the drainage (gph) of my overflows is in order to choose the correct pump (the calculator on reefcentral.com (I believe) can help me determine the drainage flow rate.
<Roughly, yes>
I have one additional question concerning the Iwakis.  Although the Japanese motors are preferred, it appears that the better choice in wet/dry return pumps is the RLXT which is only available up to the 40RLXT.  Is there a significant difference in the RLXT versus RLT models?  
<Not IMO>
I believe that I’m better off running a larger RLT than (2) smaller RLXTs.
<Agreed>
My preference would be a single larger pump (with a 2nd as an emergency back-up).  I am also planning on installing a Turbelle Stream Pump on both sides of the tank pointed towards the center front.
<Nice units>
I also have the option of running a single unit on the center
overflow (5” x 16”).  If I did this, what would be the best direction to direct the flow?
<The two... at either end... perhaps with Tunze's timer...>
I guess the more turnover, the better, so I expect that the better option would be (2) streams, one on each end of the tank.
<Yes>
  My LFS has been spraying black expanding foam on their tanks.  It looks great in their 180 display.  The overflows are hidden by this foam and it creates a nice “wall”.
<Mmm... am concerned about this material in the long haul...>
They’ve also attached frags to it.  Although it looks great, I have long-term concerns about the product’s safety.
<Me too>
  Apparently Foster & Smith were the first to offer it for aquatic use, but they didn’t recommend it for saltwater use when I called them.  They stated it was created for pond use.  I know that Julian Sprung has mentioned the use of similar products in Europe for years, but he was unsure of the long term effects of its use as well.  Are you aware of these products?    
<Am... and I expect to see Jule's "Completely revisited and revised" opinion/spiel here as well... I wouldn't use it>   
  Thanks once again for your expert advice.  Having this wealth of experience a mouse click away is invaluable.  
Scott
<Glad to share, proffer my input. Bob Fenner>

Equipment question... lack of understanding of fluid dynamics, practical plumbing, transit volume, flow rate issues, SW     02/17/07
Hello,
<Hi there>
I recently purchased a new Sedra
<I tried to talk the Macare's out of this line... and back into Eheims for their Euro skimmers...>
20000 pump and after a little adjustment in hose size finally got it on and powered up. Come to find it out it was way to powerful and sucked the sump dry.
<Mmm, mis-matched for the volume/s here>
No problem i exchanged it for a pump with about half the power 1017 GPH. I go to install this one and perfect fit all appears to be normal. Well my return from the pre filter apparently is not brining water fast enough and the new pump as well basically after an hour or so sucks the sump dry. What do you suggest I do?
<... read... till you understand the basics of fluid science here... Do a better job of planning your plumbing, transit volume, flow-rate...>
I was thinking of buying another filter with an additional hose running to the sump thus creating 2x as much water flow. If my terminology is wrong please excuse it,
I am trying to learn as I go. I have a 170 gallon Fish only tank with Live rock. The pump i have now is old and at best pumps 500 GPH. I also have two Flow master powerheads rated at 295 GPH. I know the turnover of water in the tank should be 8-10 times the tank capacity. which on the low end of 8 would be 1360gph and the high end 1700.The existing filter is an over the back box with a prefilter that drains to a "box" with another giant circle filter and bio balls then obviously the pump return the water to the tank. It has
worked for a long time, I am just afraid it is going to give out some time and I want to prevent that before it happens. I guess basically I want to know if there is a good way of improving the water flow to the sump without investing in another prefilter thing. Your help is greatly appreciated
Brian
<Please read here: http://www.wetwebmedia.com/marsetupindex2.htm
scroll down... see the pretty blue words? Read the topics you're deficient in. Bob Fenner>

Re: Sump and Return Pump Questions   2/14/07
Thanks for your prompt response.  I have a couple of additional questions.  I'm not great at math, so I would like to know if there is a way to determine how many gallons will drain from the (2) 1 1/2" overflows versus how much flow I will get from an Iwaki 100RLT (or one of the quieter models you mentioned....what pump would you recommend?).
<Mmm, there are useful approximations... much can/does affect such... issues of added plumbing, horizontal runs in particular... There is a semi-useful "calculator" posted on Reefcentral.com... In practical applications, providing for excess... occlusion... is wise. Our collective evaluations of pump choice are posted... here: http://www.wetwebmedia.com/marsetupindex2.htm
Do you see the links?>
How much of a turnover would you recommend?
<... also posted...>
I will be creating the reef with walls on the ends and an open swimming area in the middle.  Would I be better with 4 returns versus 2?  
<More than less>
I will drain each overflow separately.  Concerning the refugium in the sump, would you recommend that I place a piece of Plexiglas with a few holes in it so reduce the flow rate through the refugium?  
<Actually another bypass arrangement would be better... again...>
Do you have any additional suggestions?
<Heeeee! You're not joking I take it... sorry, just struck me as humorous>
  Would you recommend any wavemaking devices?
<Mmm, no... more gimmick than of use in most (small) hobbyist set-ups>
I would prefer not to add powerheads because I used to have a 150 gallon reef and every time I used a powerhead, it would run for a day or two, then the motor would burn up.
<There are better quality units... Look into Tunze here...>
  I sincerely appreciate your feedback.  I would much rather get things right PRIOR to establishing the tank.
  It will be much easier to do things right the first time than to correct them later.  Thanks again.
<Am in total agreement... Read... the Net, books, perhaps conferring with other hobbyists... a club? A guru there? BobF>
Scott

Wavemaker + Powerheads   1/25/07
Evening fellas,
<Hey Jason.>
Jason Here. I spoke with Justin in the past few weeks or so on a variety of different things about my 37 gal. saltwater tank with 380 GPH with head loss from the filter included. On the terms of extra water movement in the tank Justin recommended a couple maxi-jet 900's or 1200's.
<They are reliable and a good bang-for-the-buck.>
Well in my continuous search of information on the subject I ran across the listing on Dr.FosterSmith for a package deal on 3 maxi's and the natural wave system.
<I am familiar with it.>
Now for the question.
<No problem.>
Should I spring for the 3+1 deal or just pick up a few of the powerheads on their own. I don't know if the wavemaker is worth getting the bundle for but I'll include the link so you can see what I'm looking at and talking about. I appreciate the help guys. This link is the bundle:
http://www.drsfostersmith.com/Product/Prod_Display.cfm?pcatid=12061&N=2004+113040
and this link are the powerheads alone:
http://www.drsfostersmith.com/Product/Prod_Display.cfm?pcatid=4609&N=2004+113040
<These type of wavemakers make a nice aesthetic appeal but as far as it's performance vs. the powerheads by themselves there is not much to be gained, just as much...if not more....random water flow can be achieved by having the powerheads opposite each other running continuously.>
Best Regards,
<To you as well.>
Jason
<**AJ**>

Lose Those Powerheads!  1/19/07
Hey Crew,
<Hi Christian, Pufferpunk here>
I am looking to eliminate the need for powerheads in my 75 gallon saltwater tank.  To do so I would have to increase (or replace) my return pump but in doing so wouldn't I cause the tank to overflow because of too much water going in and not enough water going to the sump via the overflow? I have heard all the negative responses about powerheads and believe the risk is not worth the reward.
<I've got the perfect solution for you.  I have a Sea Swirl attached to my return & it gives fantastic flow to every inch of my tank.  I have the output directed in opposite directions.  (I do have small powerheads behind my rock though.)  They come in 3/4" & 1".  
See: http://www.marinedepot.com/md_viewItem.asp?idproduct=AU1115  As far as your concern about the overflow, you'd be surprised how much flow it can handle.  I have an extremely strong pump on my 90g & the overflow has no problems keeping up. ~PP>
Sincerely, Christian

Powerhead Setup for 86g   1/16/07
Hello,
    I am planning an 86g Fiji Biotope tank. This will have a Bubble-Tip Anemone, a pair of maroon clowns, and maybe some hard corals. There will be approx. 100 lbs of liverock. The tank is 48"L x 16"W x 26"T. What water flow setup(s) would be best for this situation?
<Mmm... this sized, shaped system... the area mimicked... the powerheads set up high, on the back sides, facing/crossing toward the middle... perhaps a smaller unit blowing through, along the bottom back of the LR. Bob Fenner>

Acrylic Aquariums    1/14/07... circ.
I appreciate your response there. There are so many things and questions running through my head and I just thought hmm I think some outside influence might help here.
<Absolutely, glad to be of service.>
Anyhow, so back to the pumps. The closed loop system for me wouldn't be as optimal. I'm inclined to use power heads but I read all about them adding too much extra heat and this and that.
<Likely of little concern here>
As of right now my sump doesn't sit under the aquarium so much as next to it. (I wish I had thought about that before I purchased the stand) As for the head on the return I'd say there's probably 4 feet plus of tubing on the way from the sump pump to the aquarium, how much does that take off my GPH if it's at 748gph at 0 head?
<Head loss is calculated with not only the length of the run, but more importantly the distance vertically from the pump to the return. See the calculator here for more help: http://www.reefs.org/pumps/>
And since I'll most likely have to spring for the power heads in tank, can you recommend anything? Nothing too powerful but enough to create the proper flow within the tank. I forgot to mention the object is to create a reef setting. Thank you in advance.
Jason
<I think a couple of MaxiJet 900's or 1200's will likely serve your tank well, with a minimal of heat addition. The 1200's will provide a bit more flow, but at a higher electricity usage (and subsequently, likely more heat production). The 900's should be fine here. -JustinN>

Increasing Water flow in Marine Aquaria…Options    6/14/06
Hi,
<Who goes there? I mean hi…..>
First, thanks in advance for any assistance that you can offer.
<Mmm…you’re welcome in advanced.>
I have been asked to take over maintenance of a marine aquarium in a doctor's office.
<Ooh the service business!>
There are some problems with the hardware setup that I can deal with.  All of the plumbing is on one side of the aquarium, in the wall.  It not easily accessible and I am working on getting that changed.  
<Yes the ease of maintenance and efficiency is by far the most important thing with “business” or “serviced” tanks in my opinion.>
My biggest concern is the fact that the water circulation is on only one side of the aquarium.
<Time to improve that!>
The algae was been uncontrollable for them.
<Probably nutrient problems here not to mention the water circulation issues….I’m willing to bet those light bulbs are old too?>
I have put additional powerheads in the aquarium which seems to control the algae.
<Effective though in my opinion not pretty, aesthetically, in a doctors office.>
The part of the tank that has little of no water circulation is my biggest concern.  I have placed a power head on that side but I don't think it is enough because nothing grows on that side.  The fish and invertebrates even avoid it.
<Time for a more drastic change like pair of Tunze streams or even better for this application a Closed Loop Manifold System.>
I was wondering if a wave maker would help.
<A wavemaker put on the current powerheads will make the powerheads create more aesthetically pleasing and turbulent flow but will not increase (“help”) with the lack of water flow by any means.>
  I have also been considering more power heads but, it is on display and I would like to keep it appealing.
I would be grateful for any suggestions you could make.
<See the above suggestions.>
Regards,
Fawn Curtis
<Good luck, Adam J.>

Re: Increasing Water Flow in Marine Aquaria  06/14/2006
Hi,
<Hello.>
Thanks for your reply.
<Anytime.>
I will research, Tunze streams and Closed Loop Manifold System since I don't know about them.
<Great.>
Just to clarify, I am not in the aquarium maintenance business.
<Oh 'okay.>
I'm just a patient who suffered near fatal brain injury.
<Sorry to hear that, but glad you are here exchanging emails with me today!>
I have been successful with my own aquariums.
Wet Web Media and the Conscientious Aquarist have been awesome resources.
<Thank for the kind words.>
Thank you very much.
<No problem.>
Best Regards,
<To you as well.>
Fawn Curtis
<Adam Jackson.>

Circulation In An 8-Foot Tank - 05/26/05
Hey Crew, Ben Here
<<Hey Ben...EricR here.>>
I'm an Aussie boy and trying to set up a large 8 foot show tank that will be setup in a show room.
<<Well maybe I'll be able to help.  I have an 8 foot show tank in my showroom (my living room).>>
I know, my dream come true.
<<Mine too <G>.>>
I was hoping I could get some advice on what the best way circulation would be on this considering that I can drill holes in the outer glass pieces.  I was going to use a 4 foot (1/4 trickle, 3/4 refuge) for my filtration with the overflow/s (should I have 1 centre or two in the centres) of the tank. Will that be enough filtration?
<<Mmm, not sure what you mean here.  If you are talking overflows I would drill for two 2" drains and use one to feed the sump, the other to feed a closed loop.>>
I have 5 powerheads if the flow isn't enough which would be good to mix up the flow but don't really look all that good.  Considering that this system will house many corals, I don’t want to skimp out of good flow.  Your thoughts.
<<Agreed...and regular powerheads will have a hard time providing good random-turbulent flow in a tank this size.  Do look in to a closed-loop flow system: http://www.wetwebmedia.com/pbretfaqs.htm>>
I hope to ask some more questions later to you guys.
Cheers heaps
Ben
<<I/we look forward to your queries.  Regards, EricR>>

Quest. regarding Lighting and flow design 4/6/04 
Just a quick hello to you all.... 
<how you doin'? > 
Have bought some of your books...Coral Propagation....Aquarium corals...would gladly buy more if you can suggest 
some others...one can never have to much information when it concerns healthy coral... 
<agreed... and Eric's book named above is one of my absolute faves. Also, do look at Fabricius and Alderslade's 2001 "Soft Corals and Sea fans". This and many other unique books can be found at www.seachallengers.com
You guys do an excellent job ,Thanks for everything..<a labor of love... but thank you for your regards, my friend> 
I am stuck with lighting and circulation decisions for my new 120 Gal display, 65 Gal sump set up.. My problem is I love large polyp stonies as well as Mushrooms and Polyps and Xenia and Basically a lot of softs.... 
<all good... reasonably close in requirements> 
But I also have a developing attraction to some SPS. 
<Arghhh... a recipe for quite a challenge to coral health and water quality in the long run. Please (!) do resist mixing such unnatural groups if you want optimal success my friend> 
Here is my Idea , please tell me if you think this 
could work. Tank is 48"L X 24"D X 24"H. Sump is 36 " L X 22 " W X 18 " H and will house a Reef Devil Deluxe and also a Turboflotor 1000 fed by Dual 1 1/2 " O.D. Durso overflows through 50 micron bags. 
<I frankly do not have much regard for either of these skimmers performance. Or rather, the Turboflotor can be made to work well with frequent tuning/babysitting or modification... but neither out of the box is consistent or reliable IMO for their price. There are much better skimmer values out there - see our archives for feedback on skimmers> 
Overflow box in tank is 17 " long by 6 " deep centered in tank. After the skimmers there is a refugium for live sand and live rock only. Then baffles, heater etc. then return portion of sump which has 1/5 hp chiller fed through bulkheads and returned to same portion of sump. Return pumps are 2 dolphin 1200's used external at 1200 GPH at 24' of head, 3/4 " outlet. One pump runs the left side of the tank and one the right side, hard piped up through overflow box. All 3/4 plumping, each one teed in overflow box to return to each corner of the tank, two outlets each pump. one outlet on each is piped down and under sand bed to lower front corners of the tank pointing up and towards center of overflow box with a 45 elbow.. (hole drilled to break siphon, in case of power out) The other is located at top rear corner of each side. Questions are as follows.....Can I satisfy such corals stated above by utilizing a lighting fixture that accommodates on one side a 175 Watt Metal Halide 10 k and on the other side a 250 watt Metal Halide 6500 K and 2 4' VHO Actinics front and back 
<the fluorescents serve little or no useful purpose for the corals (especially if they are more than 3" off the surface of the water), but do keep/enjoy them for aesthetics. The MH lamp suggestions are fine for a wide range of corals, allelopathy aside> 
to keep a large mix of SPS , LPS and possibly a Clam as well as the polyps mushrooms and few softies that I love? 
<it will work short to mid term... perhaps even several years with adequate water changes and ozone/heavy carbon to temper the excess allelopathy from unnatural corals stimulated in unnatural mixes. Still... I'd never advise such a large mix, rather focus on one group and enjoy (if you can) a teaser piece or two of the others> 
Question number 2 is....Will this pump set up be sufficient as far as water flow is concerned?<it sin the ballpark. Fine for softies... light for stonies. Try to get closer to 20X turnover per hour> 
Everything is bought and installed except for the lighting...Pumps can be changed if you suggest something other than the ones I have....No water Sand or rock yet but will have 6 " LS and about 80 LBS. LR in display and 40 LBS of LR and 4" LS in sump...Any help would be greatly appreciated....(as always :) ) 
Tank and sump was built by World Class Aquariums in Brooklyn NY....If this gets posted and anyone reads it and lives in NYC metro area.. great place to shop...!!! 
<good to hear... and if you make it out to Long Island... do check out Country Critters for rarities. The prices are dear, but the selection is one of the best around> 
Tank with 6" splash guards, Sump, overflow box ,standpipes and all plumbing ,bulkheads, made to my specifications only 900 $( Their livestock is pretty well maintained and a huge selection as well. Sure beats the puny overflows in an AGA Tank as well as Oceanic. Not to knock those companies but if you can get a custom tank for the same price...well why not... 
<yes.. agreed. Thank you for sharing!> 
Thanks for helping guys... 
Anthony Pastorelli NYC Fireman Bayside Queens... 
<best regards, Anthony>

Powerhead v. closed loop? 4/28/04
Hey Wet Web Crew!
I wanted to get your advice on my set-up, which is close to completion. 120g 48x24x24 with plans for FOWLR and some hardy inverts, possibly upgrading to full reef in the future. I have a single trapezoid overflow with 1.5in bulkhead drain and three 0.5in returns run off of two Sedra 9000s (1800 gph total at 0 head) --- I figure I may be getting 1000gph when all is said and done.
<may be too low flow for messy/larger fishes and most inverts... and really is too low to go reef. 10-20X turnover is bare minimum. Paletta (2004) cites (and I agree) with reef tanks having flow as high as 37X and the average among tanks he measured was 17X>
Now for my question, how would you go about achieving more flow?
<Ooops... you were ahead of me! My apologies>
Simplest probably would be to place a Tunze or maxi-jets in the corners,
<Tunze streamers, Tunze or Gemini top-mounts I love too... traditional powerheads I'd strongly encourage you to avoid>
but I know this produces more heat in the tank.
<among other problems... inefficiency, unsightliness, poor lifespan, increased number of units needed (versus one Tunze), increased shock hazard to you, increased noise to fishes, etc)>
I could also go with a closed loop and drill a couple more drains in the lower corners and have them return to a SeaSwirl up top;
<not bad>
could also just drill two more holes in the back upper corners as returns. Would it be worth the extra trouble to go with the closed loop?
<yes... and do consider my return pump driven top-mounted closed loop manifold idea/suggestion (see article posted on this site... find with google search tool using that term and/or my name)>
Also, (noob question here) is there a problem with small/weak fish getting sucked into the drain screens? Thx! Tom
<slight problem yes... more so with gastropods and other motile inverts. Do avoid excessive powerheads for this reason too... cage-guard others/any with coarse media that blocks animals but does not clog easily. Anthony>

Circulation problems
Adam!
  It's me again! One of my 3 SEIO 620 pumps died today -after a mere 3 months of operation. I just gave it a proper burial, and would like to do the same to the other 2 by the end of this year. These two are over 6 months old... First, I don't think with the swivel nozzle they were putting out anywhere near the claimed 620 gph output -about half that sounds reasonable.
Second they vibrate a lot. I have a bunch of dead spots in the rear corners of the aquarium with this scheme...
  My goal is to eliminate dead spots that are inherent with 2 power heads -very poor circulation just under the power heads... Plus I don't want noisy ugly powerheads anymore. I seem to have two choices.
Choice A: A pair of Tunze Turbelles stream pumps at either end of the aquarium, each rated at  1600gph. Sounds good on paper, but I may still have dead spots under the pumps and they will still be unsightly.
<< Yes, but dead spots aren't bad as long as you have a high volume flow and the surface of the water is moving. >>
Choice B: Manifold return with a 900gph Eheim pump - Maybe two of them in parallel -they cost about the same as the Turbelles. The problem here is that I have a 72G bow front tank and since they don't sell curved PVC pipes at Home depot, I won't have a closed loop! ...just an 'E' shaped manifold with the tubes running along the back and sides and one under the center brace! And the total circulation numbers will still be a lot less than the Tunze, especially since the Eheims will have a 5-3 foot head to work against. At this point they are down to 750 gph.
<< This is only partially true.  They have that 5 feet to work against, but they also have 5 feet of water above pushing down with positive force.  They lose (if built properly like a closed loop) very little pushing power.  I think a closed loop system is the way to go.  You don't need curved pipe, just build it like you would for any other tank. >>
Occupants are 1 Kole tang, 1 Ocellaris clown, 1 Fridmani Pseudo chromis, 2 Lysmata Amboinensis, 1 small xenia (in QT) and 1 Capnella (in QT), plus live rock critters.... No additions are planned, except maybe more Xenia if this one grows.
What do you think? As always, I'm grateful for your assistance.
<< I would check out some online diagrams and search for closed loop info. I think you'll be happy you did so. >>
Narayan
PS: If you are ever in the Rhode Island area, please feel free to call 401-886-XXXX...
<< Will do. Thanks >>
<<  Blundell  >>

Circulation problems continued....
Thanks Adam!
  My only concern with dead spots is that crap accumulates there, Cyano grows there and just below the surface the sand is black and smells like H2S. << Well it isn't bad for detritus to accumulate, nor for some Cyano to grow.  But the H2S is usually a bad sign.  So I'm surprised by that. >> With good flow all three don't happen. BTW, I'm replacing the Remora with a Remora Pro. Hope this helps with the Cyano without skimming too much. I want some dissolved organics for the desirable algae and coral. << Yes, it is good though to remove much of the nutrient load.  Having everything suspended (since you don't have dead spots) allows for good skimming action.  I'd also consider a filter sock.  I don't use one, but it may help here. >>
Narayan
<<  Blundell  >>

Water Movement 10/-3/03
I read the article on how to have proper water movement, but I'm unsure if my setup will do the job. I have a 50 gal.(36 x 15 x 20) aquarium with an AquaClear 300, and two Eheim powerheads, each pushing 176 gph. I have a 652 gph of total water movement, but
the placement is my concern. I have the AquaClear in the left-middle on top. One powerhead is in the upper left hand corner pushing to the lower right, and I have the other powerhead in the lower-right, pushing straight back to the other powerhead. I think the AquaClear 300 is pushing too much water for the powerhead next to is for it to have any effect. Should I move it lower? I just want to make sure I do this right, since it's very important once I have my corals involved in the picture. You guys are all awesome!
Thank you in advance!
<I wish I could help you, mate... but we have no way of answering this question. Pump placement is not about a standardized local (upper left, forward right, etc)... it is entirely case by case as influence by the individual rockscape you have designed. You simply need to adjust all such devices until you get a convergence that creates random turbulent water flow in the tank with few spots for detritus to accumulate. Very much and eyeball adjustment process. Best regards, Anthony>

Carlson Surge Device - 2/23/04
Hey Pauly, this link is no good>>> http://www.breedersregistry.gen.ca.us/Reprints/MFM/v11_aug96/simple_surge.htm
<Try now:
http://www.breeders-registry.gen.ca.us/Reprints/MFM/v11_aug96/simple_surge.htm Needed the dash! Who woulda thunk?? Paulo>

5 gallon circulation alternatives
Which of the four alternatives do you like best? Any other alternatives? Sump flow rate goal?
<Not an issue.>
Total flow rate goal?
<This is the requirement that is important, as it is in the main tank we need the circulation/water movement.>
I am setting up a 75 gallon AGA reef ready with 30 gal sump, TurboFlotor 1000.
<Cool! Not our fave skimmer, but acceptable. Look at Euro-reef and Aqua-C, much more efficient.>
The overflow is good for 600gph or less I believe. I am trying to find the best alternative to increase total circulation to acceptable level for mixed reef tank. With 4x96w PC SPS or clams are unlikely. I have purchased an Iwaki MD30RLT (510 gph) not the higher flow RXLT (ok, so my first mistake). I plan on trying one of the new Squid wave makers, may be my second mistake.
<You need at least 750 gph up to 1500 depending on inhabitants. Plan on more and turn it down if needed, use pump flow charts and factor in a healthy pump size increase to get the desired flow. Also use larger pipe throughout, you won't be disappointed.>
- Alt1 Use one predrilled hole for return line and the larger one for drain to sump and add powerheads in tank. Looks bad, failure issues, heat, looks bad.
<Yep, looks bad, works bad.>
- Alt 2 Drill additional return holes in side for closed loop systems. Tank is in basement already so trip back to the glass shop (if I can find one) not appealing.
<Or in bottom. Depends on if glass is tempered on the sides or not. Sandblasting works. A good choice with obvious considerations for you as stated. Best for desired flow, depending on flow rate allowed in option 4.>
- Alt 3 Amiracle or DIY hang on to feed the closed loop system. Of course I got a reef ready so I did not have to use a hang-on.
<Un-reliable in power outages, require powerheads to resolve siphon loss when power comes on. You have better options.>
- Alt 4 Use both predrilled holes as outlets and plumb returns over the top. Might still not be enough flow and I am not sure how the overflow would react to a larger flood over the top.
<A good option depending on flow rate. You don't give me the pipe size for these, so go to one of the WetWebMedia.com sponsors like Foster and Smith, and look at add-on overflow boxes and the passive flow rate they get from various size plumbing. Yours will do the same, but be conservative and assume the flow will be a hair less.  Add both flow rates together (for both pipes as drains) to see if it approaches what you need (anywhere from 1000-1500 GPH combined would be great). I think the overflow will handle it fine, do check out Durso set-ups and venting to increase flow and reduce noise. Plumbing the returns with a manifold and inlets over the top is not difficult and can be kept out of sight. Again, go much larger on plumbing then you think you need. Some pumps with 1" outlets only get full flow delivery with up to 2" pipe. Plan accordingly and use valves to reduce flow if needed.  Have fun with your new system!  Craig>

Water flow and carbon use 3/11/03
Dear Anthony: Thanks for the prompt reply.
<Always, welcome>
The powerhead (211 GPH) is approx. 1.0' & at a 45 degree angle from the gorgonian.
Water params:
-------------
0-5ppm NO3, 0-5ppm NO4, 0ppm NH4, 8.2 - 8.4 PH, 78-80 F TEMP., 4.0 meq ALK,1.025 SPG, 380ppm CA.
NO ACTIVATED CARBON.
WATER CHANGES: 15% WEEKLY.
LIGHT: 2X 55W PC (1 x 10,000K actinic, 1 x 7700K white)
<With only 15% water changes weekly, you really need to use carbon regularly to have any chance at maintaining water clarity for optimal light penetration. You might consider an additional power head to oppose the first one to create random turbulent water flow... laminar is harmful or at least not helpful to most corals. All else looks very fine to me :) Anthony >

Added circulation
Hi All,
I have a 75 gallon reef in which I have supplemented water movement with the addition of a single powerful PRO4 powerhead near the surface.  For the most part, I can tell I have enough current by the waving of my xenia, gorgonians and other soft corals.  However, near one side of my tank I have some button
polyps that are barely swaying and particulate matter just seems to slowly float by in that area.  I even have some spots where debris likes to settle on the live rock and brown Cyanobacteria often grows on my cabbage coral and gorgonian. I tried moving the filter outputs around, but this compromised surface turbulence.
Should I add more current?  I am concerned with the aesthetic implications of doing so, or adding too much current!  Should I have so much current that my polyps are vigorously swaying?  If they're not swaying should I be concerned?  
<Sounds like you need more circulation and perhaps a look into improving nutrient export/maintenance. I would add the powerhead to pay particular attention to the low flow area. Gauge success in placement by the results from your inhabitants and whether the Cyano returns.>
I know this maybe kind of a silly question, but I am on a quest to learn for optimal conditions in my reef and the last time I added a new power head, my mushrooms started flopping around and did not open up all the way.  Not to mention my gorgonian looked like it was in a hurricane storm.
<The Gorgonian probably wasn't affected but the mushrooms did! Place the powerhead according to your inhabitants and their needs.>
Thoughts as always much appreciated.
Regards, Steve Bihari
<Cheers, Craig>

- Water flow and circulation for 150G FO -
Hi All,
<And hello to you, JasonC here...>
I am converting a 150G soft coral reef tank to 150G FOWLR tank. I have a lot of fish in there but I am in transition in finding new homes for the small reef fishes. Also adding the new ones as I go.
I know that water flow should be high in reef tanks but how much should I keep in a fish -only system? <I'd keep things equally high...> Is there something like 5x or 10x like thing about fish-only systems. <10x is good to shoot for.>
Here are my new fish that will reside in the tank:
- Harlequin Tusk
- Emperor Angel (Bad call on my part. Needs to go back to LFS) <Would be fine in a 150.>
- Picasso Trigger
- Pyramid Angel
- Rabbitfish (double-black mark one)
I have kept some mushrooms, toad stools and softies like colts to give a little better aquascape but please let me know if you think that some of these have no chance in there. <Nah... sounds like a good list to me.> Any suggestions on keeping some cleanup crew or inverts. <Get them in there first.> Shrimp are of course a snack for the tusk. <Eventually, yes...> Any alternatives? <To a cleaner shrimp? Neon gobies - likewise, get them in there first.> Have heard about UV sterilizers a lot. Do you think having a UV in there is something I should consider. <Sure, for about two minutes and then forget about it.>
Regards,
Razi Burney
<Cheers, J -- >

FOWLR Circulation set-up
Hello WWM Crew!
I need some help for my 125-gallon (72"x18"x18") FOWLR potential set-up.  I have an acrylic tank with 1 corner overflow.  The overflow has a 1" bulkhead attached, with a hose going down to a wet/dry.  I havea Mag Drive 9.5 in the wet/dry as a return pump, which delivers 800 gph with a 4' head.  From some of your feedback to other aquarists, it sounds like that Iprobably could only get 300 gph through that overflow bulkhead.  So it appears that my return pump will be too much for one overflow to handle.  Am I correct in this conclusion?  What would happen with this scenario?
<It will overflow onto your floor!  I wouldn't do that! A 1" drain will theoretically drain approx. 600 gph. so you need another drain/overflow, larger bulkhead drain in the current set-up, (provided the skimmer box could handle 600 gph), or a smaller pump w/valve (designed for something closer to 600 gph) to control flow rate.  This depends on fish load and if 600 gph is acceptable for filtration as overall circulation will be closed loop as below.  For figuring drains and skimmer box sizes Reef Central has a nifty drain calculator in the left menu bar, check it out if that's the way you choose to go.>
And if my conclusion is correct, would you recommend adding another overflow (with a 1" bulkhead) to the other corner?  I've found a site where I can purchase a pre-fab 2-sided overflow.  Would you recommended this?  And how easy/difficult is it to install into my tank?
<Not difficult, depending on how "handy" you are.  Or have an acrylic shop match the one you have and glue it in place. Either way, you need to either go lower flow for filtration or more drain.>
I will then need to install another input bulkhead into my wet/dry (CPR CR1000--rated at 150g).
Again, would there be any negative ramifications from this modification?
<Not likely.>
Furthermore, I am planning to drill holes and install bulkheads at the back of the aquarium to run a close-loop circulation system.  My plan is to install 3 1" bulkheads near the bottom of the tank: one on the left side, another in the middle, and then one on the right side.  The one in the middle will take the incoming water to a pump, maybe an Iwaki 40RXLT, and then from the pump to a PVC T that will distribute the water to the two side bulkheads.  What are your opinions about this plan?  Do I face any problems because all 3 bulkheads are to be installed near the bottom of the tank (i.e. water pressure too much)?
<No particular problems with this at all. Do properly size pipe for both pump intake and manifold. Better to oversize one size to get full performance from pump. Use valves to control/adjust flow as needed.  Make sure the intake is properly shielded.>
I appreciate your feedback.  Your site has been very helpful to me and other aquarists in this exciting hobby! Regards, Ed
<Glad to hear it Ed! Have fun....and don't forget to QT fish first!  Craig>  

Circulation Dilemma
<Hey There! Ryan with you>
First let me commend you guys on a great site with loads of information, I never feel like I will get to the end of it!
<A wealth of knowledge!  I use it everyday as well>
My New - Future Reef Setup:
CSL retrofit 48" 2x 175wt MH / 2x 65wt PC actinic
150g Perfecto 48"x24"x30" WxDxH tank viewable from both sides, but in wall
Natures Miracle Pink Samoa Sand
Amiracle XL Mudd Sump in basement (approx 35g?) (proposed) not placed yet:
Kent Marine Bio Sediment 20 lbs
Nature Miracle Live Sand 40 lbs
1400 gph 1pc Overflow w/ 2 outlets, plumbed with 2x Lee's 1" ID vinyl hose to basement sump.
<Sounds sweet so far>
Currently 1- 3/4" ID Lee's return from sump using Supreme Mag Drive 24 1" output reduced to 3/4" pumping from basement
approx 14' high/head.  Ends in a piece of U shaped PVC with some Loc Line flex hose into tank.
There is also an extra 1" ID vinyl hose from tank to basement as a spare.
<Skimmer?>
All the hoses are new and in floor/wall behind sheetrock, and more hoses cannot be very easily added (although nothing is impossible).
<I understand>
There are no powerheads currently.
<Remedy this>
My question is this enough circulation for my tank if not, what can I do to upgrade?
My thoughts:
I can return the pump or get another pump and put it on the 1" spare back to the tank, however I am not sure the 2- 1" ID hoses can take the flow since I read a 1.5" hose has a max flow of 600 gph. Which I am to assume I have max 800 gph at most.  
Although I fear in the 1 or 2 turns in the wall behind the sheetrock, there may be some tight spots where I cannot guarantee 1" each.
<Pump should be fine- What you really need is a few powerheads aimed at each other for some sporadic water movement.  This will be of benefit to most marine aquaria.>
I have been reading through the FAQs and it seems like the Iwaki's are highly regarded as well as Gorman Rupp pumps?  <Both a fine product>
If I am to target a 10x changeover/hour that should mean about 150+35?=185x10=1800 gph at 14' head. <10-20 is recommended, you're on the lower end of the scale.  This is more reason to increase circulation in the tank itself> The Iwaki MD70RLT (1170gph) + MD
100RLT(1740) seem to be in this range.  Now my only worry is getting the
water back down to the sump, as well as the 3/4" return back to tank.
<Tinkering is the best part!>
Is the answer to get my remaining circulation from a closed loop?  If so how much would you allot to each system?
<I think you'll be fine as long as you can add some good circulation to the tank.  You may even want to direct the water upwards in an effort to keep the surface agitated.  Page 123 of Anthony and Bob's new book may be helpful in making your decision.  Best of luck! Ryan>
What should I do?
Thanks so much in advance,
Alex Wu

Circulation Dilemma Revisited
Ryan,
<Here!>
So is the answer to continue to use the existing setup that is only pushing a 2.7x turn per hour?
<Sorry if I was unclear- You need to be at 10x for a reef.>
If I look at the flow chart (http://www.pond-o-mania.com/mag-drivestats.html) for the Mag Drive 24 at 14' head it's only pushing about 500 gph on my 150g+35g=185g setup, that's 2.7x turns per hour a far cry from the 1850gph for 10x.
Therefore I should change my pumps to the Iwaki MD70RLT or the MD100RLT
BUT will the water accumulate in the tank faster than it can come down the 2- 1" inner diameter vinyl hoses back to the sump??  It seems I can only move about 800gph back to the sump.
<750 gph should be adequate with lots of circulation in the tank itself>
Therefore should I target around 750gph (4x turnover) and then make up the rest in the tank with powerheads (for the remaining 6-16x turnover to add up to overall 10x-20x turnover)?
<Yes, exactly>
If that's the case then I wanted to use SCWD's and loc line attached to the powerheads and hide everything in the LR, does that sound right?
<Yes, sounds great.>
Your other comment regarding a skimmer, I was under the impression that a Mud filter/refugium with Caulerpa didn't require a skimmer (detrimental?)  Otherwise I have a currently running FOWLR system with a venturi skimmer that I am going to rip down and move all the LR and inhabitants over to this new house.
<Actually, I was simply inquiring if you were planning on using a skimmer or not.  Many people have had success in skimmerless systems, especially when using Mud Filtration.  I'm just not one of them!>
Thanks again,
<Sure!  Sorry for the confusion>
Alex Wu

Overflowing With Questions
I am building a reef tank and have a question about overflow box location and drain hole size.  My proposed reef tank will be 84Lx24wx26(or 28)H. The sump/refugium will be located in the basement and the reef tank on the main floor.
<A great set up!>
I want to have just one overflow located at the back center of the tank; rather than one at each end.  The single middle overflow would increase the viewing areas at the sides.
<There are ways to do this...>
First:  Is there any problems with having just one middle overflow with that size tank?  It concerns me because all the manufactures build corner overflows at each end/corner.
<Although it certainly can be done with one overflow, I think that two would be a little better. Another idea, which Anthony Calfo touches on in his "Book of Coral Propagation (BTW- Just get this book- it's awesome, and you'll love it!) is to construct an overflow that runs the length of the aquarium, built near the top of the tank, with holes drilled directly into the walls of the tank. In essence, what you will have is a small shelf, which can be a neat place to place frags, etc. This is definitely a radical idea, but will efficiently pull water from the top of the water column in an efficient manner.>
Second: How large should the drain hole be in the bottom of the tank?
<Depends on the size of the pump and its flow. Larger (1-1/2" or more) is generally better, IMO>
Should I drill one large hole or two side by side?  How big? I will be using a Durso stand pipe to eliminate noise. I want to eliminate the chance that the drain does not plug and overflow the tank. Plus I am concerned one large hole may not be enough when using a stand pipe.
<Agreed- one overflow is probably not enough. I'd definitely use two, maybe more, depending on the pump size/water flow that you are shooting for. Durso standpipes work well, too!>
Third: Do you find 28" high reef tanks too tall?  I plan to use MH and VHO combo lights. Thanks for your help. Greg
<I don't think that the tank is too tall. I tend to favor wider, shallow tanks for ease of maintenance, light penetration, and aquascaping possibilities, but tall tanks work well, too, particularly if you are using a deep sand bed, creating extensive, tall aquascaping features, etc. Your lighting scheme should work; again- the suitability is largely based upon the types of animals that you will be keeping, and the wattage of the bulbs. Many, many possibilities. Have fun! Scott F.>

Re: Overflowing With Questions...
Thanks for the quick response and the thoughtful reply.  What a fantastic resource you are!
<We sure have a great group of people working here! Thanks for the encouraging words!>
Another question, though.  I am thinking about going to a 120 Oceanic "reef ready" set up, with two built-in overflows.  I think I remember reading in one of your postings that you (in the collective) did not particularly like overflows.  Is there another option for water circulation?
<To the contrary, IMO- well- designed and constructed internal overflows are the standard, preferred method of getting water into the sump from the aquarium. I feel that they are a great way to go! Maybe you were confusing external overflows, which can be problematic and can break siphon>
I have a Medusa heater/chiller controller and a 1/4 HP chiller, so I need to pump water through the chiller on the way back to the tank from the sump.
<An efficient overflow setup with a capable pump should do the trick!>
Thanks again!
<And thank you for visiting the wetwebmedia.com site. Do check on the many resources that we have regarding set-ups and sump configurations. Regards,  Scott F>

Water flow and other questions
Bob, Anthony, Steven, you've all been a big help so far answering my questions as well as the countless others. <<Must be why it's in my bucket now... JasonC here at your service.>> Thanks! I have a 72g reef in its 4th month. I am noticing red Cyano on my DSB in the corners where I assume the water flow is lowest. I have backed off on feeding (roughly 1 cube frozen mysis or krill every other day -- the active consumers are 2 Perculas, 2 Chromis, 1 Banggai cardinal, and 1 scooter blenny, and 1 peppermint shrimp) and recently added a fresh shipment of Nerites, Strombus, mini Turbos, bristleworms, micro hermits, and sand bed clams from IPSF (to the preexisting population of Turbos, Trochus, Cerith, and red hermits) in the hopes that some increased activity in the sand might help. I am also thinking of altering my water flow, and I have a few questions for you. <<Shoot...>>
This is an Oceanic RR bowfront with the return (Eheim 1060) in the upper left rear corner, aimed at the right side glass. At the upper right rear is a MJ 1200 opposing the return and alternating 40 seconds on and 40 seconds off (Natural Wave) <<I think I would leave this one on full time... the opposing flows will be plenty random.>> Both upper left and right front corners also have MJ 1200s connected to the Natural Wave, aimed along the front glass and alternating every 20 seconds. The flow is nice and turbulent for the most part and, at any given time, is theoretically between 900 and 1200 gph. In the past I have tried aiming the PHs slightly downward but it ends up creating sand drifts across the DSB. Is there a way around this? <<Put down a layer of heavy, more coarse substrate.>> Should 1 or more PHs be moved lower in the tank? <<I wouldn't.>> Should I disconnect the wave maker, or upgrade to a more powerful return pump? Or is the Cyano just a stage that will pass? <<A little of both, but I think by manipulation of the powerheads, you will eventually land on the magic placement combination. You just want to avoid those laminar flows.>>
FYI, water specs: 80 degrees, SG 1.026, ph 8.20, Alk 3.4 meq/l, Ca 420 ppm, Iodine 0.06 mg/l, Mg 1380 mg/l, NO3 2.5 mg/l, PO4 0.03 mg/l. Tank is skimmed with AquaC EV-120. Could lighting be an issue? Bulbs are all new, 2x175w 10000K MH (10 hrs) + 130w 7100K PC (12 hrs).
I realize that this is a complicated question and I hope I was descriptive enough for you to visualize. <<No worries.>> As always, I really appreciate you advice and all of the great information on the site. Thanks again! <<You are quite welcome.>>
Ed Marshall, Austin, Texas
<<Cheers, J -- >>

New tank circulation dispute, please help settle!
Hi Anthony I hope you are all well at WWM.
<very well my friend... cheers from across the pond!>
I have a problem with ordering a new tank because the FS owner doesn't agree with what I am asking for in the way of circulation. 
<hmmm... that's interesting...heehee. Is he the anti-capitalist?>
What he is recommending is 4 1/2 * the volume 
<weak... bordering on dangerous for corals>
and then make up the rest with some sort of wave making arrangement that then costs another 300+ pounds sterling (464+ US Dollars). 
<wow... he's either a crook or incompetent or both <G>. Wait a minute... maybe he's brilliant... a wavemaker is a lot more expensive to sell you than a single recirculating pump <G>! Wave makers for larger tanks in particular are poor choices for creating water movement and way overpriced by any standard. Tell him that I said, his "mother was a hamster... and his father smelled of elderberries!". Lets hope he is a Monty Python fan too :) And then tell him to read this article: http://www.wetwebmedia.com/circmarart.htm >
I have told him that you recommend trying to get at least 10* the tanks capacity through the sump. (After reading your article on Circulation) 
<awesome>
and that I would like my tank to be able to accommodate at least this through put. Am I misunderstanding you here? you do say 10*Vol through the sump instead of powerheads don't you?
<absolutely. I'm specifically saying to avoid powerheads if at all possible. They are junk technology but a necessary evil for some. A single large pump on the sump running a teed manifold (nozzles) topside (like described in the article) is perhaps one of the very best ways to provide water flow. Some aquarists that don't want high flow through their pump drill 2 holes in the main display for a closed loop in the tank run by a second external pump. The two holes can be placed anywhere and simply are plumbed together with a pump inline. This second pump never needs primed and is fairly low maintenance (do have shut offs and quick disconnects on either side though for removal and pump cleaning without draining the tank). There is much chat on the big message boards by the advanced aquarists on this strategy. I like it just fine. External pumps are longer lasting, cooler running, more energy efficient, and aesthetically discreet and hidden altogether... everything that powerheads are not>
I suggested he might look at your site , I am including his response below enclosed in this type of brackets {{ }} and would really appreciate your comments on the content so that I can feel better able to answer his objections or tell him the suggested resolutions. 
<indeed our pleasure>
He makes it seem like I'm asking for something ridiculously over the top and that I'm asking for excessive noise.
<then you are talking to a man that hasn't seen or done it successfully before <G>. Do share your plan or sketch with us here before you commit to pumps and holes, etc. Better yet... do you have a fax number we could exchange faxes at? I can send you a sketch that way>
The tank size is 5ft*2ft*2ft and will hold 125 Imperial Gallons (150 US gals approx.). Could you tell me what you would have drilled in this tank and the through put you think is reasonable for me to ask for!
<absolutely... if AMP master pumps are available... do consider. Else, a Japanese made Iwaki in the 6000 liter per hour range would be excellent (just avoid the dual pump/400 series... they are the only noisy ones in the bunch). The size of the holes to be drilled is up to you, my friend. Just check the bulkhead specs for flow tolerances. We want to exceed the pumps maximum capacity as you can imagine. If you want to do that with 5 holes for 25mm pipe, or just 2 or three larger holes (40 mm)... that is up to you. Somewhat of a personally preference here. Am I correct in recalling that you have my Book of Coral Propagation as well? If so, look at the illustrations in the early part of the book for modifying an overflow for a long drawn discreet shelf (page 42/43... and if you don't have it... I'll figure out a way to e-mail it <G>)This is tremendously quiet and drastically improves the quality of overflowing surface water. If you prefer to have the floor drilled instead, look at the illustration on the next page and modify that with a Durso standpipe... see here for instructions: (http://www.rl180reef.com/pages/standpipe/standpipe_menu.htm)>
Maybe suggest a pump that could achieve it for me.
LFS response:
{{after our discussion of last week, I read the articles within wetwebmedia.com and whilst they are of some interest I must say some of the information is very misleading, as it does not specify whether the information is in regard to trickle filters or natural reefs in most circumstances.
To give you some idea of the impracticality of flowing 2,500 gallons per hour through the sump, your aquarium would require a minimum of 4* 40 mm return pipes to sump to cope with 11,000 ltrs, this would therefore require 4 overflow boxes. The noise would be unbearable.
<this is the first problem... standing overflows (as opposed to having the back wall drilled with the internal overflow shelf... rather silent) are inherently noisy if they are not fitted with a Durso modification or like design. At any rate... sure, just drilling 4 holes in the floor of the aquarium is very noisy... but we're talking about professional installations here instead.>
please follow this link to the site of a very experienced hobbyist http://website.lineone.net/~espsrg/circulation_.htmi look forward to hearing your reply. Danny}}
I followed this link and got the impression that this aquarist was in agreement about lots of flow through but not through a DSB which I wanted to have in the sump. How would/should I handle this.
<ahhh... agreed. The DSB in the sump is an issue. Strong flow will make this challenging. There are in fact advantages to upstream refugiums rather than downstream/under sump... do consider (no plankton shear however small that may be, it becomes an aesthetic focal point... perhaps keep jellyfish or mangrove trees or something exotic in there that cannot be in the reef proper, etc). But yes... I missed the DSB in the sump bit. If its important to you... you'll have to compromise and get flow through other means like a closed loop pump in the display and a smaller sump pump, or top-mounted pumps (Gemini, Tunze Turbelle)>
I hope you don't mind me burdening you with this 
<no burden at all! It is our pleasure and duty to help>
but as I am having the tank and stand made to order I want to get it right and this chap is starting to worry me with his insistence about unbearable noise. 
<understood and agreed. Jenny, let me suggest that you find a few local aquarists to visit and see their tanks in operation with this style. Just post an open query on reefcentral.com stating you are a UK reefer from so-and-so and you're looking for a shared opinion from another local. Its a huge message board with a lot of nice folks. Seeing systems with Durso overflows and /or closed loop, 2-pump reefs will put your mind at ease and also guide you to make the very best pump and hole choices. Do you know of any local aquarium societies for like fellowship? Tell you what... I'm going to e-mail my book distributor there in the UK and see if he can help direct you locally>
Is there a minimum number of baffles/dividers needed to reduce noise or something else that needs doing?
<nope... the baffles will not likely help.>
Many thanks for your valued advice Many thanks Jenny
<And let me say again in parting, if there is a fax number that I could send you a sketch too... I will draw up a design specifically for your tank size. Else I will need to get the sketch scanned by a friend and try to e-mail it to you. Have you had a chance to glance at this illustration?: http://www.wetwebmedia.com/plumbingmarart.htm
it has some fundamental elements (some not all of use to you). Best regards, Anthony>
Jenny Nunley

Re: New tank circulation dispute, please help settle!
UK reefing
Hello again Anthony,
Thank you so much for your speedy reply and willingness to help me with my tank problem. The only fax number I have at present is my work's fax which is ################ you are welcome to use this I understand it is left on all night so should be o.k. If you would send me a sketch of what you would do I would be really grateful. 
<I just sent over several pages with a sketch of the sump fed by a horizontal internal overflow (with a profile of this apparatus on the last page) and of an optional closed loop pump as well. This one or two pump system can easily replace all other pumps for water movement if you'd consider the manifold system also sketched on page two (profile page three). This is an incredibly inexpensive way to get incredible fine tuned random turbulent water flow without any visible artifacts like powerheads in the tank display. Aesthetically very clean>
I could rethink the DSB idea if you think it has an adverse affect on the sump through put, I thought it was needed to complete the nitrogen cycle.
<I feel the DSB is quite helpful for most systems indeed! I just tend not to put it in a downstream sump but rather enjoy it in the main display proper. Your choice>
Also I have no preference on where the holes should be drilled i.e. bottom/back of tank, I will go for the back if that is the best method.
<I think the top back is best and quietest. You may use 1 or 2 large holes per 1500 gallons per hour, or 4-6 smaller holes (25-35 mm) scattered across the back. It makes little difference either way... as long as the mfg spec satisfy the flow you choose to run. Simply pick whichever you can get drilled easier with available bulkheads>
I am afraid I don't yet have a copy of your 'The Book of Coral Propagation' because I haven't yet heard back from the UK distributor you told me about so I can't yet refer to it.
<I can send you one direct if you like as well... $45USD (about 29 GBP)
Thanks again for your help, the FS will have to wait until I know what to tell him I want. Thanks again - Jenny
<do advise me if the faxes aren't legible (or intelligible <G>). I will be glad to re-fax or explain. Also see this link for an elaborated view of possible reef plumbing components: http://www.wetwebmedia.com/plumbingmarart.htm
also... here's an excerpt from my book describing the internal overflow shelf diagramed in the faxes:
"Overflows drilled into an upper sidewall of the aquarium or culturing vessel are perhaps the most common. They are easily managed and require less strategy in planning. They are generally smaller and less obvious than internal siphon overflow boxes and stand pipes. They are also the least expensive way to modify an aquarium for overflow. Holes are simply drilled with an appropriate hole saw for glass, acrylic or masonry and a plastic bulkhead is fitted. Businesses selling aquaria and ponds generally have the ability to order or complete hole drilling for customers. Careful consideration of desired water flow and pump size will determine the number and size of holes drilled for overflow. Distribution of holes along a given plane is of little significance regarding the quality of effluent water captured. Some aquarists prefer to bunch multiple holes together; others spread or split them apart. Ultimately, sufficient water flow through the display should make the debate over the distribution of holes a moot point.
What does impact the quality of water captured by an overflow is surface area. Imagine if you will, two overflow boxes each with the same sized feed that continues on a downstream path (a one inch pipe, draining to the sump, for example). If one box has a larger “mouth” (the linear surface area that the water flows over), the effluent water displaced will be spread thinner across the spillway than the smaller box. Put another way; let’s consider the same situation on an aquarium with two drilled overflow holes. If we know that the flow of circulating water can be managed by two holes operating at half capacity, then the addition of two more holes (for a total of four) should permit them to operate at a level half again as much (specifically at one fourth capacity). The surface area was doubled, so the “thickness” of effluent water overflowing was cut in half. The concentration of over flowing water is particularly important for the capture and export of proteins and other targeted matter known to migrate to the surface of seawater. The “thinnest” surface water captured will have the greatest concentrations of targeted nutrients for export by a protein skimmer or other filtration component downstream.
Beyond drilling extra holes for the over flow of water, a very simple modification to an internal overflow can be made to improve the quality of water captured. The greatest benefit will be achieved on overflows that run the length of display walls that have been drilled with holes. This can be simple and made discreet, particularly on the plane of an aquarium or culturing vessel that is not viewed through (such as the rear wall). Although the same volume of water will flow through the same given number of bulkheads had they been unassisted, the incorporation of a long, shallow overflow box will spread the given flow of water quite thin over a greater surface area (see the first illustration for this section titled, Hiding Unnatural Features of a Display). While the new feature is aesthetically more prominent than bulkheads alone, it can be hidden in a most unique and useful fashion. By extending the floor of the overflow box beyond its vertical wall by a few inches, a functional shelf is created. This shelf is in a position to receive strong light and current which is ideal for some coral species. Suitable corals may be placed on the shelf and rotated in programs of culture or allowed to encrust for aesthetic purpose. Aquarists should construct the internal overflow box as long as functional and aesthetic preferences allow. Please refer to the previous illustration on page 42 for a profile of this feature."
<best regards, Anthony>

Overflows
Can you gave me any information on the Stockman overflow I have been told it works better than the Durso. RGibson
<Cheers, Ralph! How the heck are you my friend? You've caught me in town and on e-mail for once <G>. I have been traveling so much... a great time, but I'm getting behind on phone calls and friends. Regarding the Stockman overflow... I have no personal experience with it at all. As usual, we'll post this for responses. Best regards, Anthony>

Film on Top of Water
what to do about film on top of water I have two return pumps and three power heads connected to a wave maker for water circulation still have this film on top of water can find no information any where
James mills 
<You should re-aim some of your returns or powerheads for surface agitation. Also, take a look at your overflow. This should be effectively skimming water from the surface and eliminating this scum layer. -Steven Pro>

Cycling pumps off at night time
Hello all. Last time I wrote, Bob was the only one answering questions (it's been a while). You have grown a bunch! I have a question regarding a pump in my system. I have a 125 FOWLR. I have one pump that runs full time returning water from the sump. I have another on a closed loop. The pump on the closed loop is on a timer that comes on in the a.m. a little after the actinics come on, and goes off before the lights go out at night. So the fish get more vigorous water movement during the day, and it's softer at night. Is it safe to have the closed loop pump cycle off at night, considering the water stays in the plumbing for it overnight with no movement? I know that stagnant water can cause problems, and was wondering if it applies in a situation like this. Or would you recommend just letting it run all the time, even if it doesn't cause a problem?
<From your questions, I believe you are most concerned about the stagnant water inside the plumbing giving you problems. I would not think that could be too much of a problem over 12 hours, but I have another concern. Your circulation and therefore gas exchange is weakest when your system needs it the most, at night with CO2 production at its highest. For that reason, I would run both pumps 24/7.>
Thanks a bunch! Jason
<You are welcome a bunch! -Steven Pro>

Pumps
Bob-
Do you recommend installing a pump in the back/bottom of the tank to circulate the water behind the reef?
Thank you, Rob
>>
Yes I do... as we will no doubt agree, there are very few, "well-circulated" systems... especially compared with any part of the "wild"... Many benefits to moving the water around there... no drawbacks. Bob Fenner

Powerhead Placement
One more question.......I am ordering the compact lighting that you suggested, but what about the power head placement, as I have already set up the live rock , etc. how can I cause the wave motion to create a cleaning cycle toward the back bottom of the tank?
Once again
Connie
>>
Good question... my fave placement is two to three or more (depending on size of the system, volume/flow rate of the powerheads) two towards the lower front middle of the tank from the upper back corners... But, the more the merrier (you can quote me, gladly) in the way of water movers... and I would place another small pump scooting/shooting across the back of your live rock...
Bob Fenner 

Surge Device
I was tinkering with the idea of building a surge device/wavemaker.
I remember talking to you before about the "toilet bowl" device. Do you have plans for it on your web site or are there plans on another DIY type web site?
Thanks, Steven Pro
>>
Hmm, do think there are some plans on one of the old, but still available archives of Aquarium Frontiers Online...
Bob Fenner

Reef Aquarium Question (ref.s and wavemakers)
Hi Bob,
I was wondering if you might answer a few quick questions regarding reef aquariums for me. <I'll try>I feel like I've cut my teeth on a FOWLR tank, and now I'd like to try out a reef. Can you recommend any books that will get me started? I'm looking for information such as coral compatibility, placement, care, etc. I have your book already, so any supplemental literature that you can recommend would be most welcome.
<Thank you for asking... I do agree with your approach. Do definitely get/read through volumes 1 and 2 of The Modern Coral Reef Aquarium by Sven Fossa and Alf Nilsen (some other folks would refer you to the same sorts of re-works by Delbeek and Sprung here in the US), and if you'd like a nice complementary reference, as many of the Baensch Marine Atlases (starting with number one) as you can handle... These are offered by FFExpress.com and a few of the other mail-order/internet book and pet-fish suppliers>
Secondly, what equipment is essential to running a successful reef?
Here's what I have: 180 gal aquarium w/ 200# LR, 50 gal. Berlin sump, skimmer, calcium reactor, 6 X 96W power compact lights (2 actinic and 4 daylight). Can you let me know if I'm missing anything that is a must have?
<Maybe some pumps for aeration, circulation, powering it all... many other possibilities exist depending on the type of system, your desires (culture for instance)... take a long read through the set-up parts and FAQs posted on the www.wetwebmedia.com site>
Finally, I'd like to get your opinion regarding circulation. My return pump will be a Dolphin 3000 (3000 gph) split out to two Sea Swirls, which will be placed on either side of the center brace. For additional circulation, my initial plan was to have a 1200 gph pump at each end of the tank, set up for closed loop circulation, with the returns coming out a few inches above my substrate via plumbing through the Oceanic overflow boxes. These pumps would be run via a wavemaker. However, I came across a sinusoidal valve designed by Robert Michaelson which looks like it would be a more efficient way to achieve circulation which seems like it would be more natural. (pic's attached). This valve is run with one pump, and gives varying degrees of output at each end (e.g. when as output A approaches 100% open, output B approaches 0%, then back the other way, cycling once a minute), not the simple on/off function like a wavemaker. Do you have any experience with either type of circulation system?
<Only the former... but this other design is intriguing>
Sorry to ask so many questions, but the most important thing I learned from the fish only experience was to learn as much as possible, and do everything right from the beginning. Thanks in advance for your help.
<Agreed, and you're certainly welcome. Bob Fenner>
Best Regards, DanReef 

Aquarium Circulation/pump Question
Bob,
Thanks for your help. If it's not too much trouble, could you expound a bit more on your response to my question regarding circulation? You mention that you have experience with the closed loop circulation that I described. Was it a good experience or a disaster? 
<Good>
I've heard that return pumps have been known to fail when run via a wavemaker, and I'm trying to find out about other's experiences.
<In my experience, more so than in other applications... the variable load, numerous times on/off really wear on the small units... A good idea to investigate brands and the opinions of real users ahead of actual purchase... for large-enough systems, fractional low head pumps for other applications are more desirable than many of the small, and excess heat-generating models/brands sold in the pet-fish interest...>
Thanks Again, Dan
<You're welcome. Bob Fenner>

Lighting and water flow
Hi Bob. I am setting up a 38 gallon tank that I received used. It will house marine fish and live rock. I am not too interested in invertebrates at the moment. The tank dimensions are 48"L x 10"W x 18"H. The tank has an integrated filter area in the back, which I will place mud and macroalgae, but the aforementioned dimensions correspond to the main compartment of the tank where the fish will live.
<Okay>
For lighting of the main part of the tank, I am considering a 2x55W PC set-up with the bulbs arranged end to end in a hood. After recently returning from a honeymoon in Tahiti, where my wife and I did a lot of great snorkeling, I am interested in reproducing the lighting conditions of a shallow reef environment. What Kelvin rating of bulbs would you use for such an effect? Also, while I said that I wouldn't be too interested in invertebrates, would this lighting set-up support one sea anemone in the tank (for a clownfish to play in)?
<Have been there... and this set-up should do>
For water flow, there is a return bulkhead located at the top right side of the back of the tank. A Rio pump cycles the tank at about 400 gallons per hour. How would you direct the flow of water from that bulkhead (e.g., would you split the return and if so, in which directions)? Also, would you add a power head at another location in the tank, like the bottom, for additional water flow/circulation?
<Yes to having at least one more powerhead/mini pump... and crossing the flows... please read over the FAQs section of the www.wetwebmedia.com site under the marine index for my "aiming" input>
Thank you in advance for any helpful comments. I've really appreciated all of your help in the past.
Bruce G.
<Glad to be here. Bob Fenner>

W/D
Hey Bob,
Once again I want to thank you for all of your help, but I have another question to ask you. Okay here goes, so are you saying that the Mag Drive 350 will be enough power for the 72 Gallon tank alone. Without the power heads. Or do you think the Mag drive 500 will be better for this tank. Some people think the Mag Drive 500 will be to powerful for the 72 gallon tank, then overflow the wet/dry and other say that the more power the better. Thank you so much for the Knowledge that you have provided for all of us because it is very much needed. Thanks again.
<This one pump is fine for all the filtration and circulation, aeration purposes for your 72... a bit of planning, cutting and solventing plumbing-wise here... with ball valves in place for the alternate discharges for fine tuning... Likely no added powerheads, submersible pumps needed. Bob Fenner>

Circulation
<Lorenzo Gonzalez 'playing-Bob' who's in another hemisphere right now>
For a 72 gallon bow-front tank, what would be the proper circulation using two powerheads? I want to have sufficient circulation without tossing my inhabitants throughout the tank. Would two powerheads at 270 gph be too much? Thanks for the help.
<270gph (total/combined) is not necessarily overkill for a 72g system. I like to place the powerheads facing each other, but slightly offset, on opposite ends of the tank - to create as much random turbulence as possible.
-Lorenzo>

Re: dazed & confused (from the new WWNews Chatforum.)
Hi Lorenzo---sorry to bother you through your regular e-mail but want to ask a few ?'s and don't want to take over the chat forum plus you helped me when Bob was away over initial question of powerheads. I did a lot of reading about BGA late last night and this a.m. Based on all I read...decided that anything new that was red needed to go whether or not neighbors felt some areas were macro due to small bubbles forming (?) Anyways...neighbor let me borrow his Rio2100 in case we liked the idea of it being ready to go as opposed to mag7 husband bought last night that he wants to have 3-4 pipes off of it to circulate in different directions. I'm liking the Rio (yes,  I read on WWM about some having problems) as it's on the side of my center overflow ...hits the side and comes across to the front. Can see/feel current travels the full 6'...don't know where the best placement is for my 2 -270 Hagen's...but am thinking one on the opposite back end at a different height?  I know it's hard to visualize but due you have a feeling about the rio2100 vs. the mag7 (700gph)though I don't know how much power it will have left with several pipes off of it. I spent the day brushing...vacuuming and removed some dried sea whips I had for decor which may have caused a problem due to small particles of the tang's seaweed select rinsed out. Feel I have plenty of "competition" with a 1' square area of Caulerpa...lighting is definitely enough watts (280) running 11 hours a day. I see on FAQ's re: BGA that Bob recommends adding baking soda every day to help the problem. (2 tests show phosphates at 0) Any thoughts you can pass on would be great. (Saw in one of your FAQ's that you referred to being in "Detroit's rust belt"...born and raised here and haven't heard that one?) Thanks so much---know you're very busy with the forum---BarbaraT

Powerhead placement: Mag7: Macroalgae:...
Hmm, I'll hit your 'mini-topics' one at a time, sorry if it seems terse(?)...
:-)
Powerhead placement:
Laminar currents are generally considered bad (hence the proliferation of 'wavemaker' devices) so you can avoid them by arranging your pumps such that -opposing- streams are just offset/overlapping, to create as much randomized turbulence as possible, with perhaps a vaguely circular overall current, in either the horizontal or vertical plane (doesn't matter, especially if your tank has a square cross-section).
Mag7:
Considered a premium pump by many folks, but not exactly the 'Rolls-Royce' of pumps. Still this thing might pump water through a 25' hose and out of your basement. Don't worry about the piping your hubby is scheming of - it'll be fine, especially after it's disguised by the eventual layer of coralline it will attract.
What does BGA look like:
It's mushy to the fingernail, sticks tenaciously to rocks and especially gravel/sand, frequently coming up in ugly mats. Generates the 02 bubbles you're witnessing. Red/pink/purple Coralline, on the other hand, is hard like bathtub lime-deposit, and will barely scrape off glass with a finger nail. Usually appears in little, expanding/joining spots and dots on everything, heater, filters, powerheads, glass, rocks. Just scrape it off the glass/acrylic (at least the viewing panels) early, before it becomes too attached.
Quality of RIO pumps:
Never had a problem, 'cept the stupid suction cups wear out, and the pump falls into the tank and blows sand everywhere. We have at least 10 of them, in active service. Keep hearing about everyone else's problems though'.
<Mucho... a great deal due to "user failure/neglect" assuredly>
Macroalgae:
Any algae that forms a distinctly 'plant-like' structure. BGA (bad), diatoms (bad), and coralline (good) do not qualify. Bubble/pearl (bad), Caulerpa (very good), and Halimeda (calcareous), and kelp a little big) are all examples of 'macros'.
Rust-belt: (Michigan, Pennsylvania)
I'm not from here at all, been here only 2.5 years now. Don't quite remember where I first heard the term, but note that when we lived in Kansas/Missouri for a year, very few locals referred to it as the 'Bible Belt'... but I sure did... :-)
Note too that 280 watts over a 135g is pretty much minimal wattage for a marine tank these days. I know Bob recommends the 2-4 watts/gallon, but I find 2watts/gallon extremely dim. Our 60g has 220watts, and the 35 has 96watts - both are power compacts, which are startlingly bright at rated wattages, both tanks receive 12 hours/day. The only thing you lose with the lower wattage is the ability to do things like clams, anemones, stony corals, and some soft corals. Mushrooms and Xeniids prefer lower light, like yours.
Regarding mailing me directly: I don't mind at all - but I do feel the forum misses out on the resultant discourse! Obviously I get a LOT less mail than Bob, so my responses can be a little more detailed. And as far as being 'busy with the forum' - you don't think that's my job, do you? :-) That's just for fun! Wish I could spend more time on it...
<You will my friend>
Where in Detroit/Michigan/Ohio are you? (saw you made the trip to Tropicorium)
Best regards,
Lorenzo
p.s. Cc'd to Bob, in case he has a chance to cast his Zwie Pfennig into the pot...
<I'll gladly do anything other than go through, scan and place Pond images... Agree with most all you've stated so eloquently... Are you ready for another stint as the FAQs mastah? Will post there. Be chatting. Bob Fenner>

Circulation & locations
Greetings Bob,
First thank you very much on the information regarding pump and sump size.
Next question as I work towards setting up my 5 gal <50?> reef tank concerns water movement, specifically placement of the return from the sump and location of my power heads.
The return from the sump will be at 725 gph. Is that too much flow (your recommendation of 10:1)?
<Not too much>
And, at least in my feeble brain, location of the return line should be coordinated with the placement of the power heads.
As for power heads, I have a rotating power head, a Power Sweep 228 and a 400 gph Penguin. With this plethora of information on water circulation, what would be your suggestion for placement of these three water movement devices.
<At angles to each, crossing over corner to front, along the back... no real "dead space" afforded.>
Again, I do sincerely appreciate your help and knowledge.
David Hacker
<Be chatting my friend. Bob Fenner>

Sea Swirls and powerheads together?
Good morning again, Mr. Fenner!
I'm taking advantage here of your kindness but I am a bit troubled here.
<Let's help to settle you then>
I had decided to install 2 3/4 in. Sea Swirls in my future 90 AGA (48x18x24) tank, to be established in some months from now.
<Nice units>
However, I have always been worried about circulation in the deeper zones in the tank as Sea Swirls primarily circulate water in the top. 
<You are correct>
Although this would certainly help my SPS, I am worried than lack of circulation (if any) would create dead spots in deeper zones.
The tank will have a DSB of 5 o 6 inches.
Do you recommend adding a couple of powerheads to encourage water movement in these areas or the SS would be enough?
<I think your idea is good... to add some other powerheads in the lower regions... if your substrate is fine in grade over the top of this region, perhaps pointed at oblique angles toward the mid to upper water. There are even small submersible pumps (my favorite ones by Aquarium Systems) that can be placed, aimed along the back to move water in/through the live rock areas. Bob Fenner>
Thank you,
Mary.

Re: Sea Swirls and powerheads together?
Yeah.... Thanks!
I know which pumps you are talking about, the Mini Jet Pumps...
Ok, thanks a lot!
Have a great day :-)
<Will endeavor to do so. You as well. Bob Fenner>
Mary

Water Flow Balancing
Dear Mr. Fenner:
Thank you for giving me the opportunity to ask you a question regarding my system. I, as well as everyone else that emails you, really enjoy the web site and the wealth of information it provides. I have your book (CMA) and have read through it and use it as a helpful reference. I am setting up a new tank and have placed the substrate (about 1" of aragonite) and filled the tank with water to test for flow and leaks as you recommend. I have no fish or live rock in the tank yet.
<Okay>
The set up that I have is a 165 gal (72"l x 24"w x 22"h) with two CPR C90 overflows flowing into a 10gal sump. 
<Yikes... not a very large sump... have you tested for what might happen if the power goes off?>
The raw water is pulled from this chamber by an Iwaki RLT 55 pump to an ETS Evolution 750 skimmer sitting in another 10gal sump. (These sumps are side by side with a connector bulkhead for additional capacity in case the power goes off).
<Oh! Still wouldn't fill them up very high... and would test.>
The skimmed water is pulled chamber number 2 by an Iwaki RLT 40 pump to a wet/dry filter. The water is then pulled from the wet/dry by another Iwaki RLT 55 pump to a Ocean Clear 325 cartridge filter and then to two pvc return spray bars back in the main tank.
<Lots of gear>
I let the substrate settle for about a week to reduce cloudiness and then fired the whole system up. There was still minor cloudiness in the water at initial start up but within 3-4 hours the water was so clear that at times it didn't look like there was any water in the tank.
However, the problem is that the water levels in the chambers never seem to balance out. The level in one goes up while another may go down. The reason I have this set up is so that all the water will receive all phases of water treatment.
<I understand... and would easily double the size of these sumps...>
I have ball valves on the overflow lines as well as after every pump so that is how I can vary the water flow but it never seems to stabilize.
<It won't my friend... this is part of "the universe"... best not to fight it (we won't win)... but to count of gravity (it always lets me down...>
So many set ups show the skimmer in the same sump that receives the raw water and then mixed water is sent to the return line or the wet/dry. That seemed inefficient to me, i.e. not all the water was getting all the treatments.
<Can be done... but not always the best/better strategy... in point of view of your present situation, definitely not a good idea>
Bottom line question, have I made this set up too complicated or do you think by minute adjustments it could possibly balance out? 
<If going with the two tied-together sumps would double the volume, plus... With large through hulls connecting the two... Not ever likely to "balance out"... do not count on this>
I don't want to be constantly fiddling with the valves to balance the flow. Any suggestions would be greatly appreciated, even if it means rethinking the filtration system. Thank you again for the site and the opportunity to approach you with my quandary.
Steve Morvay
<No worries my friend. A pleasure. Bob Fenner>

Circulation and Jawfish
Dear Mr. Fenner:
Have been doing research for 125 gallon reef project in planning stages. 
<Ah, good>
Questions on circulation: In a tank setup like a peninsula with only one short side facing a wall and two long and other short free for viewing, what configuration, number, and type of powerheads anchored along the back short wall would be advisable? 
<Maybe two, three... one at the top "back" corner, the other one or two at the bottom opposite or both corners... Intent is complete circulation, top, bottom and between.>
Strength and positioning of outflow needed also helpful.
<Look to the larger Hagen or A