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FAQs about Overflows, Bulkheads/Through-puts, Holes vs. Boxes... Plumbing

Related Articles: Overflow Box Arrangements, Plumbing Marine Systems, Plumbing Return Manifolds, Refugiums, 

Related FAQs: Overflows 1, Overflows 2, Overflows 3, Overflows 4, & FAQs on: Rationale/Use, Sizing, Through-Hull Fittings, Hang-On Selection, Troubleshooting/Repair... Marine Plumbing 1, Marine Plumbing 2, Marine Plumbing 3,  Marine Plumbing 4, Marine Plumbing 5, Marine Plumbing 6, Plumbing 7, Plumbing 8, Plumbing 9, Plumbing 10, Plumbing 11, Plumbing 12, Plumbing 13, Plumbing 14, Plumbing 15, Plumbing 16, Plumbing 17, Plumbing 18, Holes & Drilling, Durso Standpipes, Make Up Water Systems, Pumps, Plumbing, Circulation, Sumps, Refugiums, Marine Circulation 2, Gear Selection for Circulation, Pump Problems, Fish-Only Marine Set-ups, Fish-Only Marine Systems 2, FOWLR/Fish and Invertebrate Systems, Reef Systems, Coldwater Systems, Small Systems, Large Systems, Water Changes, Surge Devices, 


Honu says: Drains can't be practically too large, or numerous...
Bulkhead And Non-Standard Hole Size Question – 04/22/08
Hi Crew,
<<Howdy, Paul>>
I'm going to try and make this issue short and sweet because I know how busy all of you are.
<<Ah, no worries mate>>
I couldn't find this issue when searching through the site.
<<Mmm, well…guess there will be one after this [grin]>>
I am setting up my new 110g tank but I have one problem. The tank has a 1" overflow hole drilled in the bottom of the tank that was used for a wet/dry. Only 1 hole and it was previously capped off with a bulkhead/pvc/cap.
<<I see>>
It was covered with LS so it was not being used. I had to cut off the bulkhead in order to move the tank out of the stand because there was 5 inches of pipe hanging down. Now that I have the tank set up I am going to cap off the hole. I was going to do the same thing as the previous owner by using a bulkhead.
<<Hmm…do you want to keep this hole/have the hole available for use at a later time? If not, maybe a glass “patch” silicone over the hole would serve better. A double layer of inexpensive 3/16” float glass from your local Lowe’s/Home Depot/Hardware Store will do the trick (they will even cut it for you). Just cut a pair of patches to overlap two-inches beyond the perimeter of the hole…center the first patch and secure to the bottom glass of the tank with silicone (apply enough silicone to fill-out/adhere the entire surface of the patch)…next, apply a thin layer of silicone over the entire surface of the first patch and then lay/secure the second patch on top of this (use a small weight to hold all in place). The resulting “laminated” 3/8-inch patch will be quite strong and water-tight…and nothing will be sticking out the bottom of the tank to interfere with the stand and equipment below>>
To my amazement, the hole opening is 1.5". The old bulkhead barely fits in the hole and is also 1.5".
<<Can be found...though generally not from an “aquatics” source>>
As you can probably see I can't find a 1" bulkhead that will fit into a 1.5" hole.
<<Will probably take a little searching of industrial fittings, but they are out there. A good place to start is USPlastics.com>>
They all require at least 1 5/8.
<<Most of those available from hobby sources, yes (or even a 1 ¾” hole>>>
I tried to enlarge the hole using 50 grit sandpaper.
<<Mmm…save your strength>>
After 2 hours I didn't feel like I was getting anywhere and I was extremely tired.
<<Indeed>>
I'm looking for options.
<<A Dremel tool and a diamond-grit bit>>
I thought about buying a 4"x4" square of glass and silicone it, keep grinding away to enlarge the hole, or maybe you know of a 1" bulkhead that will fit into a 1.5" hole. Any thoughts on the best solution?
<<All three are viable options…but the glass patch (as I outlined) would be the easiest and “cleanest” fix, in my opinion>>
The hole will be covered with LS when the tank is up and running. Thanks as always. Your input is invaluable.
Paul
<<Always happy to share. EricR>>

Re: Bulkhead And Non-Standard Hole Size Question - 04/22/08
Thank You for your response.
<<Quite welcome>>
I was thinking the glass patch would be the best solution as well but I wasn't sure if I was going to run into any structural problems using a thinner piece of glass with all the weight on top.
<<Easy enough to “build-up” the patch to match the thickness of the glass on the tank’s bottom>>
I can get glass pieces from a local glass store. Would it be better to get 1 piece of 3/8 or is having 2 pieces siliconed together stronger.
<<The single piece of thicker glass will work…but a laminated patch “will be” stronger/more durable>>
I will definitely go the glass patch route though.
<<Excellent choice>>
Thank You.
Paul Kelly
<<A pleasure to assist. Eric Russell>>

Overflow/Plumbing Question, follow-up to ScottV ayer  4/21/08
Dear Crew,
<Hello Andy.>
I was skimming today's FAQs and saw the post from the guy who was building his in-wall setup, and Scott V warned him against the use of check-valves.
<I surely did.>
I employ a check-valve, so I was curious as to background of Scott's warning and did some searching.
<Great, an opportunity to learn! Many answers are here for those who look.>
Well, one thing lead to another, and I am now researching overflow boxes, see why this hobby costs so much money?
<Heee, it sure can, and fast.>
You start looking for one thing, and the next minute you're interested in 7 other things. So, stepping back a bit:
I have an old-school Oceanic 110 gallon display that is not reef ready. I employ one overflow box that came with my Pisces 500 wet-dry filter 20 years ago. <Wow!> I believe the bulkhead is 1.25". Accumulated air is removed through the use of a small airline siphon tube/check-valve at the top of the overflow box that drains into my sump. Water from the overflow box feeds my sump using flexible tubing, and runs into a DIY square arrangement of PVC piping (4 x 1/2" pipes connected with 4 elbows) in
which I've drilled holes (bottom and sides), which squirts water onto my bio balls (I know, I know--old school, but I have 0 ppm nitrates and the tank has been running for 1 year--someday I'll get around to removing them and replacing with LR because I stupidly placed one of my two heaters under the bio balls and can't get it out to adjust).
<If it’s not broke…>
In its original form, this unit had a sprayer arm, and the water pressure caused this arm to rotate around and spray the bio balls. I lost this sprayer arm when I was out of the hobby for a bit, so I had to design a replacement. Anyway, after passing through my sump, the water returns using a Little Giant 4-MDQX-SC (1325 gph). The pump returns water via a 4-foot 1 1/4" I.D. PVC pipe (at 4' head, I figure I have just under 1200 gph possible, but I realize my return is limited by the 1 1/4" overflow).
<Yes, to less then 500 gph.>
I've added a ball-valve to regulate flow--the pump is capable of returning much more water than can be drained.
<Good, you will need it!>
The top of this pipe is topped with a 180* elbow. To the return side of this elbow, I've added a check-valve to keep my sump from flooding in the event of a power loss/pump failure. After the check valve is a 20" (placed vertically) PVC pipe with several large holes drilled in it for
water dispersal throughout the tank. (I hope you can picture this arrangement in your head).
<Oh yes.>
So, I was able to find articles/FAQs regarding check valves, but most of the warnings seem to be aimed at those people who have tanks with holes drilled in the bottom/low in the tank.
<The warning applies to all tanks. There must be sufficient sump space for the transit volume without the check valve since it can undoubtedly fail when needed the most. The short of it is you cannot count on these valves to serve their one purpose, so why use them?>
I do see, however, that because of the way in which I've chosen to return water (i.e., 20" vertical PVC
pipe), I could face a flooding problem if the power were to go out and my check valve failed.
<This poses the potential to siphon out quite a bit of water.>
Thus, I think I would be better off changing the configuration to a horizontal drilled PVC pipe near the top of my tank.
<A smart move.>
The only thing that concerns me about this is that I will lose some of the mid/low level water movement that the vertical PVC pipe provides
now, although I think I do have plenty of flow (2 Koralia 3s at each side of the top of my tank pointed down (about 30* angle) and 2 MaxiJet 1200s about 10" from the bottom at each side).
<Directing the supplemental flow will account for the loss of flow in these areas. We are talking about relatively low flow to begin with from the return in regards to your total picture.>
So, the next thing to which my research lead me to was that I really should have two overflow boxes for redundancy.
<This is best.>
This is a valid concern, as I had a near disaster the other night when some detritus clogged my airline siphon, which allowed air to build up in the top of the overflow box that almost broke the overflow siphon.
<A common reality with these boxes.>
Do you have any suggestions as to a quality overflow box to complement my existing overflow box?
<The loaded question of the day!>
I was looking at the Cpr Aquatic CS90 (up to 125 gallons) and CS100 (up to 200 gallons).
<If you have the wherewithal to tear down your system for a half hour or so, do consider drilling through the back of your tank for an overflow. This is far and away the most reliable way to do this. Not only is this much more reliable, but YOU choose the bulkhead size, hence the flow. For an example please visit:
http://www.momsfishsupply.com/drilling_video.html
This is a (goofy) video on the basics of drilling a tank (and linked to the site on which I sell my overflows, FYI). If you are not in the mindset to tear down your tank or drill it, the hang on the back siphons like the one you have been using is your option. It is a good idea to have redundant overflows with any type, but is advisable with these in particular. The CPR overflows are nice, but I am partial to the types that use siphon tubes rather than the entire body. This keeps the water velocity in the siphon higher and will pass many of the bubbles right on through rather then accumulating them, which will break the siphon.>
My system includes a 30 gallon refugium, a 5 gallon (guess) sump, and about 95-100 lbs of live rock--don't know where that puts me in terms of total system volume.
<Me neither, perhaps back in the 110 gallon range once the rock volume is accounted for.>
Thank you so much for your help!
Andy
<Welcome, I hope this does help you decide. Regards, Scott V.>

Re: Overflow/Plumbing Question 4/21/08
Thanks Scott.
<Welcome.>
I don't think I'm ready to tear down my tank. I recently had back surgery--water changes are about all I can stand at this point. Unfortunately, my wife is neither the DIY type nor totally supportive of my obsessions . . .er . . .hobby.
<Believe me I understand both the obsession and not tearing down the tank! It was worth mentioning.>
I saw the siphon-tube type overflows for much less than the CPR (at drfosterandsmith) and just assumed there was a reason (i.e. quality/efficiency/reliability) they are $65 less than the CPR.
<The quality of the CPR units is second to none, I just personally favor the tube types for the reasons mentioned before.>
Thanks again. The link you sent was cool, by the way.
Andy
<Ahh, thank you. Best regards, Scott V.>

Re: Overflow/Plumbing Question 4/23/08
Scott,
A few last questions if you don't mind.
<No problem.>
For a redundant overflow box for my tank (knowing what I already have), what size do you recommend? There is an Eshopps PF-800 single intake (800 gph) for up to 125 gallon tank, the Eshopps PF-1000 dual intake (900 gph) for up to 200 gallon tank, and I found one on eBay made by CFL Aquatics that is a dual intake 1200 gph model. Do I need a dual intake, or can I get by with a single intake 800 gph?
<A dual intake would be better for redundancy’s sake even within the one box.>
One thing I'm a bit worried about in sizing this up is this--will adding a second overflow necessarily increase the volume of water that flows into my sump, or is it only that my system is now capable of delivering more flow to my sump (is this just a question of what goes in can only do so as fast as it goes out?).
<You are increasing your flow capability. If you do not increase your sump return output you will not increase the actual flow.>
My reason for asking is, if one overflow box fails and your pump is putting water back in the tank faster than your redundant box is capable of handling, what happens (I know the answer)?
<Yep, water on the floor. The idea of redundancy it to flow what each box can handle should the other box fail.>
I guess my question really is, how do you know that your return flow is never more than what any one of your boxes can handle?
<Pump ratings and knowing what your boxes will actually flow (not what the manufacturer claims) is a fair estimate. The only surefire way is to try each box one at a time to actually see if it can handle it. This can be pain, but you only have to do it once.>
I do intend to purchase a level controller that will kill my pump in the event the tank starts to
overflow.
<This is really not needed with overflows setup as discussed above, but an interesting idea towards an extra safety check.>
Thanks again!
Andy
<Welcome, Scott V.>

Drain and Return Layout 3/31/08
Hello everyone at WWM!! Thank for all the time you guys give to the community of Aquarium enthusiasts!
<Welcome, thank you for noticing!>
Now here's my question. I am in the planning stages of a 125 GL aquarium with a 70 GL DIY sump. I
have attached a picture of the way I am planning to drill the tank. There will be two drains and two returns. The drains will be 1.5 inch bulkheads with a Durso standpipe deal. The returns will be 1 inch and will have each have a Rio Hyperflow 26 pump flowing through them. The head is about 4 feet so I'm assuming I'll get about 1,100-1,200 GPH through each return line.
<Hmm, the drains will not handle this. A 1.5” drain is good for a little more than 750 gph safely.>
I'm thinking I'll have about 2,200- 2,400
GPH total flow in the tank. Are two 1.5" bulkheads for the drains good enough?
<No, you will need to add one more (even then you will be borderline) or step up to 2” drains.>
I have been trying to find the ratings for bulkheads in GPH but nobody really has a clear cut rating system.
<Yes, this is a matter of experience, first hand testing, or reading from those who do know! There will be such a guide out soon!>
Can the 1 inch return bulkheads handle this amount of water (1,100-1,200 GPH) flowing through them?
Or should I go bigger?
<1” is fine for this flow as a return, you can step up to 1 ¼” for this if you wish.>
Another problem I'm having is regarding the drains and their placement in the tank. In the included diagram (if you can even understand it, sorry about my novice graphic skills)
<Your diagram is fine, a view from the top.>
there is a different position for each of the drains. The placement on the left side of the tank would be my ideal location to drill, because it would free up more aquascaping possibilities, but in planning this I'm worried about dead spots that would be caused by placing it there The 2 black lines coming from each of the returns indicate the expected flow of water). There will be about two inches of no-man's land around the perimeter of the tank, except for the back if I decide to put the overflow box in that area. The other less desirable location for the overflows is on the right hand side of the diagram. I'm thinking that by moving the overflow closer to the front of the tank it will give better circulation, because the water would flow into a corner and "bounce" into other directions, but hey, I'm not an expert, so that's why I'm asking you guys :-D This position isn't my fave because it would force me to place rocks to cover the overflow more in-line with the rocks covering the returns creating a sort of "wall of rocks" look. This isn't that desirable to me as I'm going for that whole underwater canyon feeling with the mound of rock in the front-middle of the tank and the other two mounds closer to the back at the left and right. But if placing the overflows closer to the front of the tank will make everything happier than I'm not opposed to it. Your feedback is appreciated!! Sorry for taking up so
much of your time!!
<Not at all! I would put the overflows towards the back to get them out of the way. You will not have the dead spots you mentioned with sufficient circulation in the tank. Make the outputs on your returns adjustable to control where the flow goes. My concern is the size and number of the drains, as mentioned above. Scott V.>
-Art Perez

Tank Setup Update 2/27/08
Hello Crew and Bob
<Hello Brian, Scott V. with you today.>
I'm writing you today not to ask questions but to give you a update on my new reef tank ;)
<OK>
Thanks to Scott V and Mike at www.glass-holes.com I have put together the perfect reef setup. I ordered a 1500g overflow box kit which came with the diamond bit and all accessories needed for the overflow including a cool glass-holes.com tee shirt and some hard candies.
Thanks Scott and Mike
<I am happy to hear everything worked out well.>
So here's my tank setup we'll see how perfect it is as of today.
Cycling the aquarium started 2-21-08 so its 5 days old..
55 lbs of live rock from Dr Foster and Smith "Nice stuff by the way"
70 lbs of sand bed. It’s about 5 inches deep.
The sump actually overflows into the refuge...My idea but with Scott V helping me with this idea .Thanks again Scott, it works perfect.
<Good to hear.>
2 DIY refuge's 1 has 6 inches of sand other has 4 inches of refuge mud I plan on growing macro after the cycle is completed..
No light over refuge as of yet.
And then 2 Mag drive 12 pumps returning water through Vinyl Tubing 3/4" so total I'm pumping roughly 1400 gph total I'm thinking?
<I would like to state for other’s sake that I would not typically recommend this much pump on two 1 ½” bulkheads. Yours is a situation that allowed it with your particular plumbing combination and head pressure.>
Lighting is the Nova Extreme T-5 Fixtures w/Lunar Lights total watts is 216
I plan on just LPS tank at the moment..
My skimmer is junk
Skimmer I'm ordering from Scott V he just doesn't know it yet ;)
<Heee, I do now!>
Tank specs as of tonight 2-26-08 , 5:00 pm
Water is RO
Water change 10 gal weekly
Sal 1.024
<I would raise this a bit to 1.025-1.026.>
Temp 80
PH 8.2
Amm 0 ppm
Nitrite 0 ppm
Nitrate 5.0 ppm
Alk 3.0
Cal 100
I'm ignoring Alk and Cal readings above only because it’s a new tank!
I added a 2 part calcium/Alk called C-balance tonight rechecking numbers tomorrow hoping these numbers will balance (Alk 2.5 Cal 420).
<Yes, do supplement to get these numbers up.>
I'm guessing these numbers are good for the tank being 5 days old
That's about all I can think of tonight I hope I didn't leave anything out.
With all this finally done I owe many people like WWM Crew and Bob Fenner for this Web site as I am an everyday reader a BIG THANK YOU for everything you guys/gals do!  <<This is what makes all the time, daily... worthwhile. RMF>>
>:((((-<
Brian Coble, Wisconsin
<You are welcome Brian, I am glad we could help. Thank you for all the kind words and the update on your system. Scott V., in sunny California.>

Dual Overflow Question 12/23/07
WWM Crew,
<Rob>
Great work, you guys are awesome.
<The guys and gals here at Wet Web Media strive to do our best.>
I am building a 20H sump for a 50 gal tank. Head height is about 5 feet. I read through the FAQ's and found some great simple plans, and they call for a single CPR CS-50 overflow and a Mag-5 return pump. I plan on using 2 CPR CS50s overflows, per Bob F's recommendation. Should I plumb them together or drain them separately to the refugium?
<Separately, Teeing them together will give you problems.>
If I plumb them separately will I need a bigger return pump?
Do not know what pump you have now. Generally, it is best to choose a pump with a gph slightly higher than the total drain volume. In your case, with both overflows working, will be close to 600gph. You can always throttle down the return on the pump with a ball valve.>
Thanks for all you do, I am a huge fan of your site.
<You're welcome, and have a good day. James (Salty Dog)>
Rob.

Overflow Issues…Sluggish Drain Lines – 09/30/07
I just recently moved and set up my 125 Gal. tank with a 29 Gal. refugium.
<<Neat>>
About a week after having it all run smoothly, the tank has started overflowing.
<<Uh-oh>>
I have two Durso Standpipes on opposite corners of the tank using 1" piping. The two overflows were joined at a T-fitting, which led to a ball valve, then a 45 degree coupling at the end, which is about 3-4 inches below the top of the water line of the overflow section of the refugium/sump.
<<Mmm, I see…having the two drain outlets conjoin at the “ T “ reduces the overall drain capacity of the pair as you have reduced all to a “single” one-inch drain from that point on>>
I have a Pentair Quiet One 3000 (780 GPH) running the return line on 3/4" piping. After it started overflowing the tank yesterday, I re-plumbed the overflow to allow both lines to run independently into the sump at about the same depth in the sump.
<<Ah, good>>
This didn't seem to have much effect.
<<Hmm…something else must be amiss. After subsequent head-loss, I would expect the flow rate of your stated pump to be fine for the two 1” drains (figure a maximum of 300gph per drain)>>
So, I tried to silicone the vent holes on the top of the end caps, which kept the overflow from draining at all.
<<Yes, an escape route for the entrained air is a necessity. You might even try some experimentation with inserting differing lengths of rigid tubing in to these vent holes to see if you can find where the air is trapped/building and thus most efficiently expelled/released, allowing more water down the drain>>
So, I gradually enlarged the vent holes. I noticed that one end (the end that is closest to the overflow section of the sump and flows nearly straight downward into it.) has a smaller vent hole, and drains at a much slower rate than the other end.
<<Hmm, sounds like maybe the designer of the system was trying to “balance” the flow rates between the two drains…which would only be possible by limiting the flow in one, thus reducing the overall rate even further (less than the 600gph max stated earlier)>>
Could I have a snail impeding the flow that severely on that one end?
<<Is a possibility, yes>>
And if so, how do I convince it to get out?
<<It will likely require disassembly of the standpipe or “poking” it out with some type of flexible instrument (semi-rigid plastic tubing)>>
Or is it more likely that my plumbing skills really suck?
<<Hard to say without more information on your plumbing configuration. But try removing the standpipes and see how the tank drains…if you’re lucky, any re-engineering may just be limited to these>>
Any suggestions you have are greatly appreciated.
<<It may well be that your plumbing design/configuration limits the drain capacity of these outlets more than realized. Once you determine there are no blockages (snails) in the lines, install a gate-valve on the output side of the pump and adjust the to where the drains can handle the flow and see if this is suitable…a flow of only a few hundred gallons per hour through the refugium should still be fine>>
Thank you,
Jules (Portland, Oregon)
<<Happy to share. EricR (Columbia, SC)>> <Bigger drain lines... RMF>

Plumbing Apprehension…Plumbing A Siphon Overflow – 09/25/07
Dear Sirs and Ladies,
<<No need to me quite so formal mate…Eric here>>
Having some problems determining the "right" setup for my 46g acrylic bowfront.
Currently I have an Amiracle overflow dumping straight into a wet/dry via corrugated 1.25" hose, returned via an Aquaclear 70 (400gph max).
<<Ah yes, a very typical setup>>
I intend to turn the wet/dry into a sump and add a separate refugium.
<<Excellent (this is sounding familiar…I think we have traded thoughts before>>
My first question is regarding the overflow. I have read here on WWM that two overflows are always suggested regardless of tank size in case of a clogged/plugged overflow.
<<Yes indeed, this redundancy can/will pay big…eventually>>
Is this still the current thought?
<<It is>>
If I need two overflows can I simply use a model such as the CPR CS102 with dual 1" bulkheads rather than two separate (and bulky) units?
<<Certainly…as long as you only provide as much flow as recommended for one 1”-bulkhead…i.e. – 300gph
My second series of questions regards plumbing.
<<Shoot>>
Assuming one overflow: It's my understanding that the overflow will feed to a tee and that from one end of the tee it shall flow directly to the sump, from the other end of the tee I will use a gate-valve (to limit flow) and then to the refugium.
<<Sounds good>>
The refugium will feed the pump chamber of the sump.
<<Is best…allows the most refugium biota to make it to the tank rather than being caught up in the skimmer/other ancillary filtration>>
The Sump will feed back to the tank obviously.
<<Obviously>>
Is hard plumbing still recommended?
<<If you are familiar/comfortable working with such, yes. It proves the least resistance to water flow due to its smooth interior…if installed correctly. But…if you have a lot of turns or are just not comfortable working with the hard-pipe...then by all means plumb with flexible tubing, or better yet, flexible PVC>>
I have a 1" bulkhead on my overflow, can someone give me a detailed example of the plumbing pieces I will need to complete such a circuit (I am not a plumber by any means, but I am handy, just need a little help)?
<<Mmm, not without a detailed and “to scale” diagram of your system. But honestly, it is not all that difficult. The materials are not expensive…purchase an assortment of 1” ells (45- and 90- degree), tee fittings, a 10’ length of 1” pipe, and whatever else you think you might need…oh yeah, don’t forget the pipe cleaner and solvent. Then start building…if you make a mistake, no worries…start again and keep doing so until you have it just the way you like it. It really isn’t a big deal>>
If I am to use two overflows how will this complicate the plumbing?
<<Hmm, no complicating at all…feed one to the sump and the other to the refugium. Straight shot…no “tee fitting” required>>
I assume I would simply plumb one of the overflows directly to the sump rather than use a second tee.
<<Ah yes!>>
Thanks for any help, it is greatly appreciated.
<<Happy to share. Eric Russell>>

Sump/Overflow Question…Best Way To Temper Flow? – 09/01/07
Good morning all,
<<Greetings Daryl…evening now>>
Thank you again for the world of info on your website.
<<A collaborative effort…we hope you find it useful>>
I hope this finds you well.
<<Doing fine, thank you>>
I recently moved my 55-gallon FOWLR to a 75-gallon aquarium with an overflow. In the 55 I was using a canister filter and skimmer; the 75 is my first venture with a sump.
<<A worthwhile change/upgrade>>
I am currently using my CPR hang-on skimmer with the 75, planning on eventually using a skimmer in the sump instead.
<<Ah good…perhaps one from my current fave, Euro-Reef>>
The sump is a Megaflow 2, which is sized for a 75-gallon aquarium; my return pump is rated at 950 gal/hr. Sump intake is through a 1 1/4" hose and is output through a 3/4" hose connected to the pump (not split). My question is this: The volume of water coming into the sump tends to overflow the prefilter pad daily; I rinse or change the pad, which quiets things down for awhile, but in about 24 hours I am back to overflowing the pad.
<<Perhaps a coarser pad would not clog to quickly>>
The water in the overflow bubble chamber is approximately 3/4" above the prefilter tray, which seems (to me) a bit much.
<<Why, what problem is this causing?>>
What is the best way to lessen the water coming in to the sump?
<<Reduce the volume of water being pumped up to the tank>>
Am I better off installing a valve on the intake to lessen the flow into the sump, or would I be better off splitting the return to the tank?
<<Don’t place a valve on the drain line, but rather, install a “gate-valve” on the “output” side of the pump to temper flow as needed>>
My guess is that splitting the return would be a better option, as I would also increase water movement with a second output, but I would very much appreciate your opinion.
<<You can split the return if you wish…but do still install the valve for best “control” of the flow rate>>
Thank you in advance for all your help.
<<Happy to assist>>
All good wishes,
Daryl
<<And to you in kind. EricR>>

Re: Sump/Overflow Question…Best Way To Temper Flow? – 09/03/07
Sorry to bother again...very quick follow up:
<<Hey Daryl! No bother mate>>
I have a check-valve on the output of my pump.
<<Is a mistake to use/rely on these devices in my opinion. Much better to design/install plumbing such that the sump will handle all transient water volume. The check-valve imparts significant resistance requiring a larger pump (and associated cost/energy consumption) than normal, and will most assuredly fail at some point>>
If I install a gate-valve, should it go inline before or after the check valve? I would assume the gate-valve would come first, followed by the check-valve...
<<This might be fine (If you are determined to keep the check-valve). Though depending on the size/type of valve and how much you need to reduce flow, you may find that the valve stops all flow before the desired rate is reached if the gate-valve is installed first. This is probably of little concern, but a bit of experimentation will tell>>
Thank you again, and all good wishes,
Daryl
<<Happy to help. EricR>>

Connecting Overflow PVC with Silicone Only?   5/20/07
Hello Crew!  Jason here from Manila.  Hope all is well with you.
<Yes my friend, thank you>
I've read on your FAQs how you support using silicone (vs. cement) on threaded PVC fittings, as you can easily pull it out when you wish.
<Yes... make a nice, cushioned seat...>
I have PVC going out of my overflow bulkheads, that I would like to use Silicone (vs. cement) as I will have an extremely difficult time removing it if the pieces are cemented together.
<Yes... have to be cut, replaced if solvented...>
I am not able to get threaded fittings, unless I make my tubing bulky with extra PVC pieces (which I do not want to do if I can help it).  So I have slip PVC pieces.  Can silicone provide a proper seal on slip PVC pieces?
<Mmm, no... too likely these joints will pull apart>
I am not running any pumps thru these.
The water running thru here is from my overflow, into my sump.
Hope you guys can help!
Jason
<Perhaps looking for, using "unions" (a type of re-joinable PVC fitting) will work out better for you here. Bob Fenner>

Pump For 72 Gal Bow Front? - 03/27/06
Hello Crew.
<<Howdy Steve>>
I just purchased an All-Glass 72 gal bow front that will be used for a FOWLR set up.
<<cool>>
The tank came with the predrilled MegaFlow Overflow.
<<Mmm...is hardly “mega”>>
The overflow has a 1-inch drain, ¾-inch return, and max flow rate of 600 gph.
<<More like half that actually.  You “might” get the drain to flow close to the 600gph rating, but not without much fiddling/tuning/modification of the plumbing to handle the associated surge and noise issues>>
I am shopping for a return pump to be used in the sump of my wet/dry, and I am currently looking at these brands:
1) Eheim Hobby Pump 1260 @634 gph or Eheim 1262 @898 gph
2) Mag Drive 7 @700 gph or Mag 9.5 @950 gph
3) Quiet One 3000 @780 gph
Which pump would you recommend in terms of durability, ease of maintenance, and quietness?
<<The Eheim...hands down the best of the three.  And do plumb with a gate-valve between the pump and the return to moderate flow as necessary>>
Are there other brands that I should consider?
<<You could, but not necessary in my opinion>>
Any assistance that you can provide is greatly appreciated.  Thanks for such a great site.  Keep up the good work.
Steve
<<Thank you for your participation.  Regards, EricR>>

Re: Pump for 72 Gal Bow Front? - 03/27/06
Eric,
<<Steve>>
Thank you for your recommendation on the pump.
<<Quite welcome>>
Can a gate-valve be used if I wanted to use flexible tubing for the return?
<<It can...you will need to thread barb-fittings in to the threaded valve to accommodate the flexible tubing...or...get a valve with slip-fittings and use "flexible" PVC...a much better alternative to the vinyl tubing in my opinion>>
Or will I need to plumb the return with pvc?
<<Not necessary as stated>>
What can I do to address the surge and noise issues that you refer to?
<<Mostly a matter of experimentation and trial and error my friend.  Adjusting run lengths/angles/bends, aspirating, terminating above/below the water-line, etc., etc....  Do read through our info on plumbing marine systems>>
Thanks,
Steve
<<Be chatting, EricR>>

Combine Closed-Loop Intake and Sump Drain In Horizontal Overflow? 03/26/07
Hello,
<<Howdy>>
I want to first say I think your site is great and it has helped me a lot in planning my first reef tank.
<<Glad it has been of use>>
I do have a question though that has been somewhat answered but only in general terms.
<<Ok>>
I am hoping if I give you some specific details you can tell me if a closed-loop intake in my overflow will work quietly.
<<Mmmm...I’ll see what I can do>>
I have a horizontal overflow that is 16 inches long and 4 inches on each side and 4 inches deep.  It will be mounted in the middle of my 50-gallon (36x15x20).  This will give me 24 inches of linear overflow.
<<Agreed>>
It does have teeth cut into it; the cuts are 3/8" wide and 1 1/4" deep.  I know the teeth violate the Calfo-principle but I had it made before I did all my reading here and would still like to use it.
<<Ha!  No worries mate...am sure Anthony will forgive...>>
I was planning on putting 4-1" bulkheads in the overflow.  Two would be used to drain to the sump, one would do, but I wanted some redundancy.
<<Redundancy is always a good idea>>
The other two would be joined with a wye to a single 1" flex PVC and go to the closed-loop pump, a Blueline 40 HD-X capable of 1270gph @ 0' head (1" intake and output).  Using a Mag-3 for the sump return, and the Blueline for the closed-loop, I am figuring I will actually flow no more than 1100 to 1200 gph.  If I used down turned elbows on the drains, will I able to drain this much water from the overflow and not suck in air or have a lot of noise?
<<I'm not sure how this configuration will "balance out."  The presence of the closed-loop intake in the skimmer box will cause more water to be pushed/pulled in than you intend your "sump" overflows to handle.  And though the pump intake may be more "aggressive" than the gravity drains, I think they will still "drain" more water than you intend causing noise/bubble issues...and possibly even "starving" the closed-loop pump which could lead to more noise/bubble problems.  I think it will be better if you don't try to incorporate the loop intakes in to the overflow box.  This configuration would also recirculate much of the oily surface film through the loop, rather than letting it go to the sump for the skimmer to remove.  Since the design of a true closed-loop precludes the tank draining in the event of a power outage/pump failure, I recommend you drill/place the throughputs for the closed-loop "outside" and below the horizontal overflow box>>
Should I just not bother trying this and just put two bulkheads in the overflow and drill the other two below the overflow for the CLS?
<<Ahh, yes!...is what I would do>>
Thanks WWM crew!
<<Happy to share.  EricR>>

SW pump, plumbing et al. wonderings  - 04/22/2006
Thanks for the great website.  I've looked through the FAQs but can't find the answer to my question so I apologize if you've answered this before.  I have a 215 gallon Oceanic FOWLR that I eventually want to go reef.  I want to switch to an external pump to both increase turnover and reduce heat.  I want to max out on the turnover but I don't know how to figure out what that would be given my outlet system.  I have two built in overflow boxes in the rear corners that have 1" bulkheads leading to the sump.  What would be the max flow rate external pump that I can purchase that won't pump in faster than it can drain?
<Mmm, depends on a few other factors... but I would shoot for a pump that moves 5-600 gph... perhaps a bit more, at the head difference you intend... and throttle the discharge down with valving...>
I currently have an internal pump but don't know what GPH it is.  It was a package deal so I am assuming it is the lowest I could get away with.  They also set it up with PVC extensions raising the water level in the overflow boxes to lower waterfall noise.  Will I have to take these out to max out the system?
<Mmm, no... once again, depends on what particular livestock, arrangement of hard decor...>
I've had a persistent nitrate problem, will the increased flow help to keep organics in suspension and increase their removal?
<Yes... one of a few general benefits>
Thanks for any help you can give.
<Do give a/nother read through the Plumbing, Pump Selection... sections linked here: http://wetwebmedia.com/marsetupindex2.htm
Bob Fenner>

Re: Overflow rates ... and... sump plumbing period  - 04/19/06
Again thanks for taking the time to answer my questions.
<Yikes... if pertinent, pls include prev. corr. We have no way of easily tracing who you were chatting with, about...>
I have a 55 gal. reef that I am setting up a 10 gal. refugium (small I know but necessary due to space constraints, and I figure some is better than
none). I have a CPR overflow box that is rated at 600 Gph. It comes with a 1.250 bulkhead fitting. I want to use flex tubing for the drain line
to the Ref. What size pump should I use for the return?
<... a "small one"... Providing perhaps three to five times turn over maximum... a need to be cautious here due to the small size of the sump itself... the real possibility of it overflowing with transit volume should the pump fail>
Should I put in some kind of valve in order to help balance the overflow with the return?
<A good idea... though better if the pump were "about right" w/o valving>
Can I just install the overflow w/1.250 flex tube and a clamp and run it to the refugium and then .625 or .750 flex from the pump back to the tank? Thanks.
<Mmm, yes. Over-the top... I do encourage you to read here: http://wetwebmedia.com/refugium.htm
Particularly the linked files at top on Design, pumps/plumbing... Bob Fenner>
Jay W. Thom

Standpipe plumbing, bubble-madness (and noise if you're really lucky!)  - 5/12/2006
Hi guys I need some serious help. I just purchased a 75gal to replace a 75gal that was old and leaking. I got an All-glass with the MegaFlow overflow already installed.
<Hopefully one with the larger through-put/holes>
Ever since I installed it and turned it on, I have been having a problem with air bubbles in the drain line from the tank into my sump. Is there anything that can be done to correct this?
<... some>
It is the standard 1 1/4" standpipe with drilled aquarium bulkhead fitting, then it goes straight down to a flexible pipe (pool hose stuff) and into a 20gal sump.
<... have you tried aspirating this line?>
I have tried to raise the standpipe, lower the pipe etc. I do not understand why the air is getting into the drain line.
<It is "entrained"...>
Before I used the stand pipe, I had a corner overflow, with bioballs, on the drain line I had a valve and that regulated the flow so I would not empty the overflow. I have tried this with the standpipe and it does not seem to work. when you slow the flow, the water stacks up in the overflow.  
I am at my wits end at this point and am very unhappy with the whole MegaFlow/standpipe thing. It looks like it might be  a great setup, but mine just isn't working properly. any help would be greatly appreciated. I have a Quiet one pump to supply water back to the tank, not sure what the size is but I have not changed it from tank to tank.  
Thanks,
Chris
<Mmm, this technique is described in various places on WWM, but basically, inserting a length (to be determined... so don't cut it just yet) of rigid or flexible "air-line" diameter tubing... nominally 3/16" into the standpipe... and trying this at different depths within the standpipe... should yield relief from the "entrainment"... try this and see. Otherwise, do Google on/with WWM re this issue, or read here: http://wetwebmedia.com/bubtroubfaqs.htm
and the linked files above, where you lead yourself. Bob Fenner>

Overflow that would be sticking out of the bottom that the nut screws now plumbing...?  6/29/06
Hello all,
It is Gary Austin again.  I have a Perfecto 125gal. reef ready aquarium.  I also just received a new Lifereef sump and skimmer system.  I was dry fitting the sump, skimmer, and had one of the overflow packages in my living room and noticed a small issue.  I had the drain pipe in my hand with the bulkhead fitting and nut.  I have figured out how to install the overflows in the tank but need some advice on connecting the hose/flex tube to the overflow bulkhead.  I was told that the threaded end sticking out of the bottom that the nut screws onto should not have a female connection used to hook up to the drain tube.  I looked at the bulkhead and appears that it is designed for a 1" pvc pipe to slide into it.  If I do this then I would have to glue a piece of 1" pipe then add a fitting with a 1" hose barb end to connect to 1" flex tubing.  The 3/4" returns are the same.  Is this correct or can I screw a fitting right onto the threaded end of the bulkhead to make my connection? !
<I would do this latter Gary... No sense, and I mean no sense in reducing the not-so-reef-ready diameter by inserting pipe, using flexible on this end when you can thread over it...>
  I would prefer to use a female threaded connection in case I need to tear it apart.  Please let me know if I have this right or not?  I hope this makes sense as it is quite late and my eyes are failing me here.  Thanks a bunch and keep up the great work.
<Take a bunch of deep breaths, and don't cut/solvent anything until you're "calm"... Realize what your options are. If there are threads on the discharge side, use a smear of Silastic or Teflon Tape, and thread a female fitting over these. Bob Fenner>

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

SW plumbing, overflows mostly  - 09/01/06
I am in the process of setting up a new aquarium and wanted to run the set up by the great team at WWM to see if there are any clear issues.
< 20+ heads are better than one! >
My new tank should be 170 gallons measuring 60"x25"x25". It will have a 40" horizontal weir overflow with 4 1" bulkheads. There will be 2 1" bulkheads for the return. I am looking to set up a small sump tank under the cabinet to take in all the overflows and run the skimmer. The water will then flow down to my basement using a 2" PVC
< You may want to consider multiple 2" lines. > <<And this size through-puts/bulkheads... the one-inchers won't do here. RMF>>
to my main sump which will be larger and contain a refugium. I will then use an Iwaki pump to return the water back up.
< A MD-100RLT, I presume! Great pumps. >
I wanted to keep the skimmer on the first floor because it's more convenient to clean but keep the rest in the basement because of easy access to water.
< Sounds great! The only concern I would have is the ability for the single 2" line to handle the flow from four 1" bulkheads. Simply doubling up should suffice. Good luck! RichardB > <<Mmm, what's that formula for the surface area of a circle? pi R squared.... do the math. Surprised? RMF>>

A Plethora of Plumbing Questions - 08/31/06
Hello,
<<Howdy>>
I have a few questions regarding plumbing my 120 tank to my sump.
<<Alrighty>>
I am setting this up as a FOWLR now, but planning for the flow for a full reef later.
<<Mmm, no reason your FOWLR shouldn't have this benefit as well>>
I have been reading WWM daily to get a good idea of how to plan things, I just wanted to run this info past you to see if all is good.
<<Ok...let's see what you've got>>
I have a 120(48x24x24)gal tank, it will be built into the wall with a utility room in the rear, so space is not a big issue.
<<Cool!>>
I am going to have it drilled locally at a glass shop.  I am going to use two 1-1/4" bulkheads for drill-bit size reasons.  I have 2 bulkheads to be installed that are 1-1/4"ID.  These will both feed the sump.  I plan on having them drilled aprox 5" from center to the top of the tank (in the corners), and in the tank, use two 1-1/4" 90's with a threaded strainer to skim the top.
<<Ah, yes...this is very similar to my drain/overflow configuration>>
After coming out of the back of the tank, I will use a reducer to go to 1-1/2" pipe.  I know that it will only flow the equivalent of the 1-1/4" flow bulkhead, but the 1-1/2" pipe is more readily available
<<Indeed>>
-What is the flow of each 1-1/4"?
<<There are many things that can "revise" what is essentially a laboratory environment/best possible scenario flow calculation...  The flow calculator on Reef Central says you can flow 920 gph through a 1.25" bulkhead drain...experience has taught me that reality is about HALF the calculated rate.  You can squeeze out more, but for reasons of complexity/noise/hassle you will be better off adding more throughputs if you need/desire more flow than this>>
From the reducer it will go into a T-wye for better flow movement, and will run above the tank a few inches to be topped off with a cap on each Over-Flow that will be drilled at the top to allow for air to vent.  
<<You'll find inserting a length of tubing through the vent-hole in to the pipe a short ways will be more efficient than the vent-hole alone>>
Then running down via a 1-1/2" pipe it will go into the sump via a 1 1/4" reducer.
<<...?>>
My sump lid is already drilled for the 1 1/4".
<<Ah!...I see now>>
Will this second size change hurt flow at all?
<<Will be a "slight" hindrance/increase in friction as the water navigates the "bump in the road">>
I plan on having 2 unions installed and 2 gate valves.
<<Unions are fine, but I wouldn't put valves on the drain lines...too much flow restriction and chance for blockage>>
I will also allow for an additional T somewhere in there for convenient water changes and maybe feeding a fuge later.
<<Good planning>>
OK, with this said, here are a few of my questions:
-What do you think my total flow will be with the 2 1-1/4" bulkheads?
<<As outlined previously...about 900 gph or so, before things start to become problematic>>
-Do I need to go to 1-1/2" bulkheads?
<<If you want more flow than this, yes.  But I see no reason to push more water than this through your sump.  You may want to consider additional throughputs for a closed-loop for more water movement within the display tank>>
-Is converting to the 1-1/2" in the middle causing any flow issues?
<<No>>
-Where in here should I put my UV?
<<Mmm...should not be plumbed in-line with the drain>>
Should it just get its feed from the sump and use
a pump or add another T + reducer to use gravity to feed the flow with a gate valve?
<<Best configured/flow regulated through a dedicated pump>>
-Will the UV just return to the sump?
<<Up to you...can be plumbed to simply recirculate in the sump if you wish...or can be plumbed from the sump to the display>>
It's a 15-watt (I know it's a little small but I'm using it for now) will it do any good?
<<Again, up to you...its efficiency will depend greatly on how diligent you are about keeping the lamp sleeve clean...but yes, will likely provide "some" benefit, though these units are more trouble than they're worth in many cases...in my humble opinion>>
-I have an in sump skimmer, should be OK..??
<<No idea/not enough info, but if it came with the sump I have doubts as to its quality/efficiency>>
-Will running 45's instead of sweeping 90's matter for me?
<<If true "sweeps"...no>>
-My sump is 30x12x14T, is this big enough for this flow?
<<Many variables to be considered here (plumbing configuration, dynamic water levels, transient water volume, etc., and not the least of which, your (your spouse's) tolerance for noise), but generally speaking this should handle 900 gph just fine>>
I will start with the bio balls and evaluate later to remove.
-For now I would like to go with an in sump pump, maybe a MAG, can I use just one pump and feed it up to a "T" with two over tank feeds?
<<You can>>  
-Or should I use two pumps???$$$$
<<A single pump suitably sized will serve fine.  My advice would be to "oversize" the pump slightly and install a gate-valve on the output side to temper flow as needed.  You'll appreciate the extra power/push once the plumbing lines begin to restrict from the inevitable build-up of bio-film>>
-I would like to just use one, can I get enough flow to turn the water over 10-15 times an hour?
<<Not with two 1.25" bulkhead drains...nor may you want to push this much water through the sump...but at any rate, this much flow will require more or bigger throughputs>>
-If I use just one, what size would you recommend to return lines before and after the "T"?
<<Best to follow the manufacturer's recommendations>>
Or if, I use two with no "T" what size line?  Can I start with one pump and a "T" setup to save $$ and change later to two later?
<<Sure...changing to two pumps is not necessary, though having the "built-in" redundancy is not a bad thing in case of a pump failure>>
-What size pump, in flow - do you recommend for this setup?
<<A Mag-12, with previously mentioned gate-valve installed>>
Which in-sump pump is best for low heat?
<<The MagDrive pump work well for me>>
-Are gate- or ball-valves better for me?
<<Gate-valves...much easier to make fine adjustments>>
-Would this whole thing work better with an external pump?
<<Either can do the job...but a submersible pump is usually easier to employ>>
Whew!!!!  Thanks so much for taking the time to help with my, I mean our, Obsession!!!
<<Indeed my friend...I'm happy to assist>>
Hopefully this all makes sense to you.
<<Yes>>
And sorry for all the questions!
<<No worries>>
BTW, this is tank #4 in my house, I'm finally growing up at 36, and getting away from the hang on filters.
Randy
<<Good luck with your project, EricR...49 as of yesterday and still not quite grown up>>

120 gallon tank drilling pipe setup   9/16/06
I currently have a 75 gallon reef aquarium.  I bought a 120 gallon 6 foot long X 18 d X 21 tall aquarium that I want to have drilled for sump X 2 and refugium X 1.  If you think this is possible.
<Mmm... better to go with two good-sized overflows and use "Tees" and valves for water distribution below>
  I was going to make a total of six holes.  Two holes would be for outtake and return from under the tank wet/dry filter (it only has one intake hose), two holes for outtake and return for under the tank sump holding rock, sand, and mangroves (any other suggestions for what should be in this, such as mud, etc?)
<... posted on WWM. Read here: http://www.wetwebmedia.com/marsetupindex2.htm>
and two holes for outtake and return for above tank refugium containing rock, copepods, amphipods, Chaetomorpha, etc.  Where should I have these holes drilled and how would you hook up the system (which hole goes to and returns each system.
<Also posted>
  I saw you mention something about cages instead of an internal overflow, where can I get cages?
<Such thread on intake screens are available from online and not outfits like MarineDepot.com and All Seas if you're a dealer>
  Do you have pictures of a tank with cages instead of an internal overflow?  I want to avoid using power heads as well, Will the two returns
from the sump and filter be enough circulation?  Any suggestions you can give me that might make this better would be appreciated.
  Thanks Stephanie
<Keep reading my young friend... you're not quite "there." Bob Fenner>

Re: 120 gallon tank drilling pipe setup   9/17/06
Can you send me the passage on the slender horizontal overflow, does anyone make these for purchase?
   <... what? Please... keep reading. BobF>

Micro-Bubbles/Drain Line Plumbing - 10/14/06
I have a 215G Oceanic Reef-Ready that came as is from the factory.  I thought I did my homework and then some when ordering this tank, but I have since learned that the drains are inadequate for this size tank.
<<A common enough opinion/fact that you'd think the manufacturer would eventually "get it">>
Re-drilling this thing really is not an option at this point so I need to make best with the situation that I have.
<<Can be done, yes>>
I'm running 2 Mag-Drive 7's for my returns, I'm figuring that I'm pushing about 700-800gph combined with the 2 pumps after figuring in head pressure.
<<This should pretty much "max out" the 1" drains>>
I have two Vortec pumps to provide additional circulation within the aquarium.
<<Excellent>>
The two 1" drains are handling this with no real noise issues.
<<Good...often this is not the case>>
The problem I'm having is with micro-bubbles, I'm not sure if this would be related at all to the inadequate drains.
<<Could be/probably is...nowhere for the entrained air to go...>>
I'm doing a container with a container sump system using Rubbermaid Totes.  I figured that my problem was the result of not enough baffling, but I have since read the opinion of one of your crew members that micro-bubbles are not the result of the water returning from the drain, instead they are only formed in pressurized situations.
<<Hmm...>>
Is this fact, or just his opinion?
<<I have no wish to second-guess others of the Crew (especially without knowing the reasoning), but I suspect both (opinion based on some fact).  But that said, I don't agree that micro-bubbles would only be present in "pressurized situations."  As with the case of venturi-style skimmers, the bubbles can be the result of trapped air and water turbulence...in "my" opinion.  Maybe it comes down to the individual interpretations for "micro-bubbles," but I have witnessed some very fine bubbles emitting from drain lines over the years>>
I poured a glass of water in my tank and saw large bubbles near the surface and very fine bubbles deeper in the tank, similar to the micro-bubbles that I have.
<<Indeed...much the same as what is happening in your drain lines>>
If it is true then my problem must lie within my plumbing work or the pumps themselves.
<<Bingo!>>
I don't want to reconfigure my baffling setup if I'm not getting rid of the source.
<<Hmm...well...supposedly the "baffling" should handle any bubble issues (is why it is there), but excessive quantities of very small bubbles can be very difficult to "baffle out."  I agree with your stance to attach the source of the bubbles>>
I did the Vaseline test on all plumbing connections and that didn't seem to help.
<<Do be sure to clean the joints of any residual Vaseline to preclude possible deterioration of the plastic from the petroleum elements (Bob "cringes" at the use of this product).  It's likely the problem stems from the fact you have the drains pretty much at their maximum potential.  "Noise" isn't the only problem associated with overloaded drains.  I think your problem is entrained air due to the amount of water you're pushing through these 1" drains...aspirating the drains may provide relief.  This involves inserting small-diameter tubing at the highest point in the line to allow trapped air a route of escape.  The exact diameter and length of insertion requires a bit of experimentation>>
I have two 30G totes as my main sumps, linked together through bulkheads.  One was going to be a refugium.  I'm now thinking that perhaps I should now use the refugium tote to provide additional room for dealing with the micro-bubbles so I can have more containers and hence more baffling.
<<Mmm, I like the idea of the refugium.  I would look to aspirating the drain lines...you could also try using just one return pump to reduce flow in the drains (would still be plenty of flow through the sump/refugium in my opinion>>
I also seem to have what appears to be a bunch of fine particles in my saltwater, like dust in the air, only seen when turning the lights off and shining a light through the tank from one side and viewing from another.
<<Hmm, do you have a fine substrate?  Bioturbators?  I wouldn't be concerned>>
I'm sure after all the work I have been doing in an attempt to rid myself of the bubbles I have introduced a good bit of dust into the tank.  The tank was filled with purified water, so the source is not my source water.  But I'm not sure if this can be related in anyway to micro-bubble formation, or if everyone who did the same thing would see it in their tanks as well.   Can you tell me what would be the best way in using a sump system such as this to filter out these fine particles?
<<Some folks use filter socks on their returns.  I am not a fan of these as they trap detritus (obviously) and require constant maintenance/attention to keep them clean/become a source of decaying organics.  Personally, I wouldn't bother/worry about some particulates in the water>>
I have already drained this tank once, and it would take a lot to have to do so again.
<<I see no reason to drain the tank>>
Please let me know any input you can provide for my situation.
<<Have done so...>>
I hope this post is coherent; I have been up late trying to work this thing out.  but I'm determined to do so.
<<No doubt you will>>
Thanks,
Kevin
<<Regards, EricR>>

Plumbing/Overflow And Pump Size 10/6/06
Hello,
<Hello Wayne>
I am setting up a 35 gallon marine tank with a 20g sump. My question is what size overflow should I use since the tank is not drilled. I was planning on connecting a 1/10 hp chiller to the sump with the return to the main tank.  The chiller recommends a flow of 200-300 gph with 5/8in tube fittings. Would a CS50 overflow box be o.k. or should I go with the CS90. Also, what pump flow would you recommend.
<First, I would recommend nothing lower than a 400gph pump.  You will lose some gph through the chiller and the return line.  A flow control can always be put on the pump outlet to regulate flow.  The CS50 is only rated at 300gph flow rate, so I'd go with the CS90.  For additional info on subject, read here and linked files above.  http://www.wetwebmedia.com/plumbingmarart.htm>  
Thanks in advance.
<You're welcome.  James (Salty Dog)>
Wayne

Re: New Predator Tank Stocking, actually plumbing/overflow Advice   10/29/06
Thanks for all your advice Bob, where can I send your Christmas present??
<Mmm, the Red Cross?>
On the comments about my 'emergency drain' on my smaller tank.  I think perhaps you misread what I was getting at.  I already have a corner overflow with a drain out the bottom of my tank to my sump.  My water level in my overflow remains at approximately 3" during normal operation.  I am thinking of putting my emergency drain within the overflow compartment perhaps about 5" from the bottom of the overflow on the back or side of the glass.  If there was a power failure... Simply my pump would not continue to fill my tank and tank water would lower to the level of my overflow draining out the bottom drain.  It wouldn't have any effect on the emergency bulkhead drain.  The only instance in which the emergency bulkhead would come into play would be if the strainer on the primary bulkhead drain would become clogged thus allowing the overflow water to rise beyond 5" and then the water would have the same drainage capacity as my primary overflow.
<Ah, I see now>
Correct?  Two 1 1/4" drains on a 90 gallon tank should be sufficient since my primary drain already easily handles the tank flow?
<Yes>
On my 200gallon tank, which is becoming the predator tank I described below, I only have the one drain and my pump that would be rated at 1,775gph overflows the overflow and raises the tank water and runs my sump dry.  Thank god I did a trial run on freshwater and nothing else is in the tank.  I've emptied my freshwater and someone's coming out on Friday to drill a second 1 1/2" drain on this tank.
<I'd have multiple... oh, I see this addressed below>
I'm wondering though, If my existing drain is not sufficient to handle the water flow, adding a second drain would handle the water inflow... But if either one of them becomes clogged... My sump will run dry.  I was so paranoid of my 200 gallon tank overflowing and flooding my developed basement... I made it virtually impossible to overflow my tank... Pretty much in every instance my sump will run dry long before my tank overflows.  Is it better to add as second hole within the existing overflow several inches up the back of it?
<I'd keep at the same level.>
  Should I possibly add another overflow box within the tank and add a third drain?  i.e. one overflow contains two drains and the other overflow contains one drain?
<Yes>
3 drains total and obviously the highest positioned drain serving as my emergency drain?
Dave
<A good plan. BobF>

Marine Plumbing, drains/overflows...  10/24/06
     Hey there, I mailed you quite a while with a question on waterproofing a homemade sump. Thanks for the advice you gave me, it worked out well if you remember.. I was thinking about getting my sump rhino lined.. yes it sounds dumb now).
<Actually... polyethylene... just expensive in HI>
Anyway, I was hopping you would be able to give me a little more of that great advice. I did lots of searching on your site but its a little hard to find the right search words.. all the wrong topics keep coming up. So, the problem... I currently have a 240gal 24x24x96 tank. My drain lines cannot handle the amount of water my pump is putting into the tank.
<... not unusual a situation>
I have two 1.5" drains with Durso style standpipes in the overflow boxes. The pump is the SUPER quiet sequence dart. The pump is pushing water up through about 6 feet of head, which according to the pumps flow charts should be giving me somewhere near 2400gph. Now a 1.5" drain should give me 60gpm right ?
<Mmm, no... not in the real world>
(I got that on your site with another person you helped out) Then two 1.5" drains should give me 120 gpm or 7200gph. Now considering that my pump is pumping out at around 2400gph I know I have a design flaw. Even if the pump had no head its max output is rated at 3600 gph which is still way under what my overflows should be able to do. So here it goes, ill start with the left side overflow and run you down the pipes.
     The standpipes drains about 1" below the waterline. The water then falls down about 20" to the bulkhead. Under the tank I have a union placed right up against the bottom of the bulkhead. After the union the water falls 6" down to a 45elbow then travels 6" horizontally to another 45elbow, through a bulkhead with another 45elbow sending the water falling 15" or so to a submerged output. I'm going to be putting a micron bag on this line. The submerging keeps it nice and quiet.
<Yes>
     The overflow on the right is identical until you get past the union on the underside of the tank. After that union the water drops about 6" to a 45elbow then about 8" horizontally to another 45elbow sending it (still horizontally) to a tee. The tee has unions on both side and 45elbows going into two bulkheads for the two separate chambers of my wet/dry. To do something about the noise and the velocity of water tearing the blue filter pad to shreds) I have two small bowls that sit on the wet/dries blue filter, the bulkheads output are submerged in these bowls about 2".
<Good technique>
     So to sum it up, the left side has two bulkheads, one union and three 45elbows to a submerged output. The right side has 3 bulkheads( two are on separate lines after the tee) four 45elbows ( two on separate lines after the tee) three unions, and one tee, going into a submerged output ( really didn't mean for this to start sounding like a riddle hehe). All the plumbing is in 1.5" and I though that maybe the air holes at the top of the standpipes weren't big enough.
<Mmmm...>
So I took the tops off  and let the noise all out. It still nearly overflowed my tank. Could it be that my standpipes need more head pressure to deliver more flow?
<No/pe>
should I try to lower them?
<Won't help much... not appreciably>
Or could it be that having both my lines submerged has left the air nowhere to go but up making it hard for water to go down? I don't know but, Am hopping you do.
<No more hopping/hoping...>
     The last time you gave me advice you mentioned you have a home on the big island.
<Yes, in Holualoa... on the 180... just down from K. Komo market>
I hope you weren't there for the quake and your house is ok. anyway... hoping for some good advice over on Oahu.. take care
<Thank you... What you "really" need are more and or larger overflows... two, make that three 2" inside diameter... the rest of the plumbing configuration detailed is fine... not contributing to your lack of flow potential... Either re-drilling the tank and re-doing the plumbing or changing the delivered water to the main tank (a smaller pump, diverting part of the flow... a restriction valve...) are your easy alternatives. A hui ho! Bob Fenner in Thailand>
Mahalo nui loa -Chris

R2: Hard Plumbing...Soft Plumbing...Pump Intakes...Bulkheads - 10/20/06
Hi Eric,
<<Hello Ken>>
Thanks again.
<<Always welcome>>
Few more questions if it is ok?
<<Sure>>
What do you suggest that I use from my 1" bulkhead return to my sump in terms of piping or tubing.  The bulkhead is pretty much right on top of the sump.  Do I use PVC straight down, or angle it somewhat, or tubing.
<<I would use rigid PVC straight in to the sump with a 45-degree ell on the end positioned just below the water's surface.  The ell helps to clear bubbles so they aren't trying to go back up the pipe/creating resistance like a "straight-in shot" would>>
I am asking the question based on what may be the quietest with the standpipe in the tank.
<<Understood>>
I thought I read somewhere that straight down was not the best option.
<<Thus the reason for the ell/for placing the output below the surface>>
When I fill the tank with water the first time and run the system to check for leaks:
A) Can I keep this water and go with it or do I need to change it due to new tank, tubing, piping, etc.
<<Should be fine to "keep">>
I was wondering if there is anything that could be bad for the live rock or livestock once I stock the tank?
<<Mmm...be sure to follow proper cycling protocol for newly established systems>>
B) How long can I run the system without lighting (except room lighting) without putting anything into the tank?
<<Theoretically speaking...indefinitely...but I like to put light on my rock while curing/cycling the tank, and let the natural algae progression take its course>>
I was wondering if I would get algae if I ran it for a couple of three days with nothing in it, as I am not sure what day I am getting my rock.
<<No matter...will happen eventually>>
I used to use Reef Crystals many years ago when I had a reef tank. Is this still good?
<<Will be fine>>
My tank is 90 gallons with a Marine Technical Concepts HSA-1000 skimmer, and their Pro-Cal calcium reactor, Maristar HQI (2x250 watts) and T5 (2x54 watts), and two Tunze Turbelle Stream 6000's with controller.  How many pounds of live rock do I need?
<<I like to go with a "bit less" than most would suggest for reasons of aesthetics/giving the organisms room to move around/grow.  I would start with about 60lbs of a premium rock and make adjustments as need from there>>
Is it 1.5 lbs per gallon or less than that?
<<A useless measurement in my opinion...to many variables (weight of the rock, type system/ancillary equipment employed, species/type animals, etc.)>>
It is supposed to be Fiji.
<<Should be fine...though some regard this rock as "bargain" rock>>
It is from LFS and it is as cured as you are going to see from a store.
<<I would still expect/allow for this in your tank...albeit likely diminished>>
I will also use the packaged live sand too (for aesthetics mostly), maybe about 3/4" or so (depth ok?).
<<Yes>>
Is the Carib-Sea live sand or the Nature's Ocean a better choice?
<<Waste of money in my opinion...use dry aragonite and let the rock seed the sand>>
Is there a certain grain size that I should be using, and do I have to put this under the rock or can I put the rock in the tank first, and then the sand up to it?
<<A mix of grades from sugar-size to 2mm is fine...and yes, for stability placing the rock on the tank bottom and then adding the sand works fine>>
I think I used up my quota of questions.  Thank you so much for your help.
<<No worries mate...we're here to help>>
Regards,
Ken
<<Be chatting.  Eric Russell>>

Hard Plumbing... Soft Plumbing... Pump Intakes... Bulkheads - 10/19/06
Hi Eric,
<<Hello Ken>>
Thanks for the response.
<<Quite welcome>>
In between I sent you my email and saw your response I had discovered the world of flexible PVC.
<<Ah...>>
I used this with PVC glue.
<<Yep>>
I used 3/4" and 1" for my two pumps.  I did a smooth curve (not a loop).
<<Excellent>>
It probably took 15" -18" to make the smooth curve.  I would imagine that this should be ok?
<<Will be fine>>
Does this stuff definitely hold?
<<If you installed it correctly, yes...is as strong or stronger than schedule-40 PVC hard pipe>>
I also put a union on the suction side.  Is this ok?
<<Yes...and a good idea to facilitate maintenance of the pump>>
I figure that in case I ever have to take the pump out this would be the simplest.
<<Indeed>>
I would imagine that I should put a ball valve somewhere on the discharge side.  What do you think?
<<I agree, but not a ball-valve...instead install a "gate-valve" as this will give you a much finer control of the flow.  You should also consider placing a union between the pump-discharge and the gate-valve for the same reason you placed one on the intake side of the pump>>
I know some people would say put a valve on both ends of the pump due to sump drainage if the pump is removed but I could always take some PVC pipe and a 90 degree elbow and some more pipe and put it higher than the water line.
<<If this is your "return pump" it should not be an issue as you should have the sump plumbed in such a way as to hold all the transient water when the pump is off.  Thus, once you turn off the pump and allow the tank to drain down, water from the drain line/pump intake line wouldn't be a problem>>
I am trying to keep as many "add-ons" out of my plumbing.
<<Always good>>
Of course I need to lose some gph anyway since the pump is rated at 790 GPH at 5-feet of head and the tank can only handle 600 GPH.
<<No worries, the gate-valve will allow any final adjustment if necessary...and I think you will find that 600 GPH will be too much for the single 1" drain to handle easily>>
One more question about the standpipe with the Mega Flow.
<<Okay>>
Is this noisy?
<<Usually, yes...you will probably want to consider a modification.  Do a Google search re "Durso Standpipe" or "Stockman Standpipe"...I think both offer "kits" for these now>>
I was curious why I read about people switching to the Durso standpipe.  Do you have any ideas on this?
<<Indeed...most hobbyists find the "stock" standpipes supplied by the tank manufacturers to be about as inadequate as the throughputs themselves>>
Also, is there a trick to "tuning" either of these standpipes?
<<Should be listed on the respective websites, but generally, aspirating the drains sometimes proves helpful>>
Oh yea, and I did replace the two bulkheads that came with the tank.
<<Ah, very good>>
Thanks a lot.
Regards,
Ken
<<Pleased to share, EricR>>

Overflows and returns  11/16/06
First off, I want to thank you for all your help. This is truly a great website to help hobbyists like me. I am trying to plumb a new tank and had a question about combining lines. My tank has 2 1" returns and 2 1.5" drains. I wanted to know if I can T the 2 returns with a 1.5" PVC pipe
<Can>
and T the 2 drains into a 1.5" PVC pipe
<This I would not do... better by far to run both 1 1/2" lines down independently to the sump>
so that I have one PVC pipe draining into my sump and one return pump. I know you usually want to T 2 smaller sizes into a larger sized PVC pipe but since my returns are only 1" I wanted to know if I could T the 2 1.5" drains with a 1.5" PVC.
<I would not... too much likelihood of restricting the flow to too large a degree. Bob Fenner>

70 gallon plumbing  9/20/05
Hi Bob!
Do you think that two  3/4 inch bulkhead overflows will be enough to handle the output from a 3100 Rio pump that puts out 900 gal per hour?
<Ah, no>
Do you have any bad advice for making a sump out of Rubbermaid containers?
<... posted on WWM... Bob Fenner>
Thank you for any input!
-Steve Balogh

Re: Tank/Sump/Plumbing   3/3/06
James, thanks for the response and I apologize for the poor grammar.  After looking at the sump diagram on OzReef.org, I have a few final questions about the sump:
I'm going to use two bulkheads for my return lines, using LocLine and flare nozzles to replace my powerheads.  Should I connect each return to a separate pump, or would I be better off using one powerful pump to power both returns? <I like the idea of two separate pumps.  The "T" connector will reduce the flow of both pumps close to 10%.> If one pump is used, how powerful should it be and will I get equal pressure in both returns (using a t/y connector)? (mag drive, 55 gallon, 4 foot head max). <Here is a link to some flow calculators so you can select the correct pump.  http://www.reefcentral.com/calc/hlc2.php>
How large should my drain and return bulkheads be for this size of an aquarium? I'm assuming the return bulkheads should be smaller in diameter than the drain? Would it be safer to install two drains, or would I be alright with one large drain? <One drain will work and pipe sizes can also be determined in the above link.  Look on the left sidebar for different calculators.> Do issues generally arise in the ability of the pumps to drain the sump as fast as the drain line fills it, or in the ability of the drain lines to fill the sump fast enough to keep the pump(s) from running dry? I want to use vinyl tubing instead of PVC to connect the sump and the display tank. <Obviously we don't want a pump that is capable of pumping more water than the sump can receive.  This info can be found on the link also.>
Do the return and drain bulkheads have to be on an equal plane against the back of the tank? I plan to place them high up on the tank. <I would put them on a equal plane.  You have to protect yourself in the event of a power failure so you don't overflow your sump and putting the drains/returns too low will cause this.  You may want to consider check valves on the returns to prevent a siphon should this occur, but if your sump is sized properly this shouldn't happen.>   Thank you once again.  Sorry about the relentless e-mails, but your help is and has been invaluable to me. <Understand.  James (Salty Dog)>

CPR BakPak to overflow conversion   03/9/06
Hello, <Hi Craig.>
I am wondering what your thoughts are on plumbing my CPR BakPak to a new refugium I would like to add to my tank.  I am thinking I can plumb a stand pipe though the bottom of the BakPak which would flow to a newly placed refugium tank and plumb a return line back into the display tank. Have you heard of anyone else doing this? Are there any obvious reasons why I would not want to do this? It seems to me that I can save a good chunk of money by using what I already have laying around. <Seems to me like very little water would be processed through the skimmer itself rendering the skimmer close to useless.  Other problem is  what if your return pump in the refugium quits...how much water are we going to pump into the refugium before the CPR pump starts cavitating from lack of water.  I'd think about it my friend.  James (Salty Dog)>
Thank you!
-Craig

Overflow Noise - 03/04/06
Greetings crew-
<<Hello Penny>>
I have emailed in the past, and received a very informative response, so here I go again.
<<Hopefully I will live up to your expectations.>>
I have read FAQs until my eyes hurt; posted questions on all the forums I'm a member of; asked friends...done all I could before I decided to bug you guys.  
<<Not "bugging" us, really.>>
Here's my problem:  the water overflowing from my main tank into my sump/fuge is very very loud.
<<A common problem.>>
I finally got all the other noises under control and I just can't figure out how to get this one down.  
<<Let's see if I can help.>>
My setup:  I have a 105 gallon Oceanic (does this make a difference?) with a single overflow.
<<Depends...how much water are you trying to push through this?>>
The over flow uses a 1.5" tube.  The water flows through the Durso standpipe setup that was provided with the tank into the sump.
<<Ah yes, the standpipe is 1.5" but I believe the bulkhead/drain are only 1".>>
Here's where the noise happens.  It sounds like Niagara Falls.  Then it flows into the 'fuge section, and finally into the return section.  We were using a CA3000 pump, but at 1000gph, were told this was too much.
<<Indeed>>
We replaced it with a Mag7, which solved the problem we were having with the flushing/burping sound.
<<Mmm, still might be too much...depending on head height, you may find a Mag5 will solve your problem.>>
The water is returned to the tank through a .75" tube/pipe.  (All 'soft' plumbing).  If you need more information on my setup, please let me know.  Any thoughts on this?
<<Plenty...I think you are still trying to push too much water through that single 1" overflow, I recommend you try to turn no more than 300/350 gph through your sump.  Believe me, it will make a difference.  If you need more flow than this in your tank; and you do, use a larger pump to plumb a closed-loop for the system.>>
Thanks in advance for your help!
-Penny
<<Regards, EricR>>

Overflow Capacity/Plumbing Questions....
Hi Guys,
<Hi.>
I've read through all the Marine Plumbing and circulation FAQs, but I just wanted to get your opinion(s) on the setup that I am contemplating. I'm going to set up a 55 gallon acrylic (36x18x20) to house LPS and SPS, in addition there will be a 40-55 gallon sump located in the stand. I was thinking about having two 1 1/2" holes in the bottom of the overflow box as well as two 3/4 inch returns between the two. The overflows would drain directly down to my sump/skimmer and would then be pumped back up to a closed manifold via two separate in sump pumps (for redundancy). Do you think this system could handle a flow rate of the roughly 1500gph? 
<Yes.> 
Could it handle more? 
<The plumbing could... not sure what would happen in the tank.> 
What would you do if this were your own system? 
<Get a larger tank... the more space you have, the easier it is to keep in balance, pull off things like high circulation systems. In a small tank you run the risk of having such turbulent flow that water will slosh all over the place. Certainly will make it hard to keep a sand substrate in place on the bottom. Otherwise, your plan for redundancy and increasing the drain size is all sound.> Thanks in advance for any and all responses.  Josh
<Cheers, J -- >

125 plumbing
Hello to all.
I will soon be plumbing my 125 RR AGA and have a question. The tank has the standard 2 overflows w/ 1" and .75" bulkheads in each overflow. I am planning on using both 1" and 1 - .75" bulkheads for the drains to the sump. I will use valves to adjust the flow to the sump. 
<Why would you want to do this? No need for it.> 
Then use the other .75" bulkhead for the return. My return pump is a Mag 18 and will be plumbed to a manifold running along the top back of the tank feeding 3 outlets. Does this sound reasonable? 
<I would put a valve on the pump in the event the pump puts more water into the tank than the drains can provide.> James (Salty Dog)> 

Plumbing and Stuff
Hey crew,
My brother is on his way up from Southern Cali bringing me my brand new 135G glass tank.  72"X18"X24".  I am gonna make it a FOWLR predator tank:
200 lbs. of Florida crushed coral substrate, is that too much?
<Try it and see... should be thin or rather deep... see WWM re>
80 lbs. of Caribbean Live Rock from Drs. F&S
Home made 40G sump w/balls
EV180 w/ Mag 7
Soooo, I was planning on using a Gen-X PCX-40 rated at 1190GPH w/22' max head for the return pump.  I will only be at about 5' of head.  I contacted the company who I bought the tank from and they said the bottom pane is tempered and the sides aren't.  The tank is a complete virgin with no holes.
  I know it is a no no to drill tempered but, is it impossible for even the pros to do?
<Can be done>
  Someone like Custom Glass?
<Or other glass companies around you... call them re>
If so, I will then have to go through the side.  I can only have one overflow because of where the tank is being placed, so by going through the bottom back of the tank, what size bulkhead would you use?  I was thinking about 2".
<Should work... if placed low enough... when/where in doubt, make it larger... can be regulated on the discharge side>
It sounds excessive, but it has to go directly into a 90 degree elbow.  Do you see any problem with that size because of the elbow?
<Will slow down flow a bit... I encourage you to use a Tee instead... for venting, noise reduction... read on WWM re>
Also it will then have to Y off to go into two separate chambers of balls.  I read over the faq's on plumbing and got a lot of mixed opinions.
<Then... keep reading till you have your own ideas of how to proceed>
I just don't want to have the wrong size hole drilled.
Now to my DIY sump.  I might have a good idea.  It's a 40G three foot tank.  
I want to use two five gallon buckets filled with bio balls.  It seems like a lot but the fish are big and messy.  My main concern is keeping the nitrates as low as possible between the faithful bi-weekly water changes.  
<Skip the wet-dry media (balls) if you want to avoid nitrate bottle necking>
Most wet/dry's with 4 gallons of media say they're good for 150G.  So by having two going, when the nitrates got too high, I could pull one bucket and clean em up while the other 5 gallons are still holding the bio load.  
What do you think?
<Won't work... but go ahead and try this... you can always pull them>
Finally, I would like to try out UGJ.(under gravel jets)  Have you heard of anyone using this idea on a s/w tank?
<Yes>
I got the idea from http://www.vatoelvis.com/135g.php.  He uses it for cichlids, but I like the idea.  Maybe it would help with circulation at least?
<Maybe>
Well, as usual, I'm up at 3:00 a.m., searching the site, and the rest of the web, for anything new I have not seen yet.  Thanks for the reply whenever you get the time.  The site is wonderful, and I'm looking forward to some new books from you guys.                    Thanks, Mike
<Keep reading and keeping good notes Mike... you'll do fine. Bob Fenner>

135G FOWLR follow-up, cutting glass, overflows, LR over the Net, plumbing and WWM pix
Thank you for the reply Bob, I have just a few more questions and then I should be good at least until I get this thing set up.  I talked to a bunch of glass shops in the area, and they all said they would drill the sides, but no one will touch the tempered bottom (can't say I blame em)  With that, they also told me they cannot guarantee the sides will not break while drilling, but they will do it.  That worries me.  If it would happen to anyone, it would happen to me (I know Murphy very well)  So that leads me to overflow boxes, which also worry me.
<I'm more worried about the latter than the former in terms of potential for trouble>
But then I stumbled onto Lifereef.com, telling me that he hasn't had one malfunction in fifteen years.
<Wow! Well, maybe "he" hasn't... but how about their customers?>
I value your opinion very much and was wondering which route would you take?  
<In almost all scenarios to have the tank pre-drilled if possible before assembly, or drilled after...>
Actually, in your experience, are these custom glass places known for busting even annealed walls, or are they just covering there butts?
<Methinks the latter>
Secondly, I was planning on Caribbean rock for Dr. F&S, and then I found a listing on eBay, Item number: 4381101282, can you please take a look and tell me if this stuff is any good?  
<Mmm, did so... out of Ft. Lauderdale...>
I emailed them and asked about size pieces and they said to just let em know what I'm looking for.  Too good to be true?
<... do you want Caribbean, Florida rock? The South Pacific sources are better for general purposes... cheaper per volume, function>
Finally, please don't laugh, but in your last reply, you mentioned nitrate bottle necking.  I don't understand what that means.  Can you please explain it to me?  Thank you.
<Sure... by "driving" the forward reaction/s of nitrification... lots of aerobic space, oxygenated water, water flow... nitrate tends to accumulate in high/er concentrations... the means, mechanisms for nitrate conversion into other matter are impeded... and hence "bottle necking" (backing up in the reaction series) occurs>
P.S.  I would like to send a couple of pics of my DIY wet/dry, but I don't know what you mean when you talk about file size.
<Kilobytes, megabytes... we prefer a few hundred Kbytes size maximum... jpegs, bmps preferably>
  Oh yeah, that reminds me, if I have only one 8" baffle right after the bio ball chamber, will the other side of the baffle remain at a 8" depth, even though the bulkhead for the pump is only about 2" high?  Thanks again, I love you guys.              
Mike
<If your water flow is not too fast and I understand what you mean here, yes. Bob Fenner>

- Overflow and Plumbing Flow Rates -
How much over flow (max) do you feel a 1.5 inch overflow can handle, per hour? <Well... please keep in mind that these are two separate questions. A 1.5" piece of tubing can flow roughly 3,500 GPH. The "overflow" may [in fact probably will] limit this by the size and number of slots that allow water to pass through it.> Now, how much do you feel it should handle, being conservative and safe? <Again, depends on the manufacturer of the overflow.>
Same questions for a 3/4 inch overflow (for a 90 gallon oceanic, drilled with a 1.5 and 3/4, I was contemplating using both for overflow, but at a rate well below what each could handle collectively). <Not entirely sure. Know that Oceanic/AllGlass have improved their overflow boxes to handle higher flow rates, but you should really get in touch with them to see if their overflow box will in fact handle what you're looking to push through it.> hear that 1.5 inch can max out at 750 GPH, maybe I'm wrong. <Do believe it's more that that. The old style AllGlass overflows could handle 900 GPH per overflow box, the Oceanic ones could handle about 1200 GPH> Not sure of the safe/reasonable level. <Again, should contact the manufacturer.> I haven't seen info. on a 3/4 as it relates to "overflow". Thanks very much.
<Cheers, J -- >

Overflow Tube Size
Hi guys/gals- <<And hello to you...>>
I am looking for your guidance once again. I am setting up a 125 AGA salt tank & 2 corner overflows with fish and live rock. An upgrade from a 5yr old 55gal set up. <<Interesting, just moved my 54 into a 180... have fun!>>
I have been told that the 1" bulkheads will move about 600gph each. If I stepped the 1" pipe up to a 1 1/4" right after it is connected to the overflow at the bottom of the tank, will this improve the flow rate at all? <<Not above and beyond what you can get through a 1" bulkhead, but I think that is actually higher than 600gph - I think this specification may be that of the overflow.>> I would still have the 1" bulkheads but I thought the larger diameter would move more volume from that point on. <<The bulkhead is the limiting factor, even though it's not really limiting you.>>
I have a 2 magdrive12 pumps and am not sure if I need both or not. If I used both I think would need more overflow than the 1" bulkheads can provide. correct? <<Well, I think this pump is rated at something like 900-ish at a 4' head, and even this would be more than 600-gph per overflow. I'd try it when you do your leak test, and just plumb in valves on both pumps so you can dial them back a notch. More flow is always better if you can do it.>> 
I am keeping Tangs (Naso, Sailfin, regal blue and yellow) ,live rock and 2 Condy anemone, lots of snails/hermits. Plus an arrow crab. I have a 30 gal refugium and a 20 gal sump.
Do you think that my tank would benefit from the increased flow from two mag12 pumps? <<Oh yes.>> Could I use both pumps and close down the shut-off valve a little bit on both without damaging the pumps? <<Any restriction/valve placed on a pump should be done after the pump... if there is a valve in front of the pump, use this only to shut off the line and remove the pump for service.>>
I am not sure if this idea is nuts or not...... <<nuts... you mean like true-unions? These are excellent - use them everywhere you hard-plumb. Or do you mean the nuts on the bulkheads? If these make you nervous, smear some aquarium silicone on the gasket and put it together. It will be fine.>>
Could I tap off of a overflow line with a T and run some water into the refugium and have the overflow from the refugium tap back into the same overflow line farther down line? No pumps involved. Both T's would be before the sump. <<You could - might be best to try and arrange the refugium above the sump so that it could overflow into the sump. Is this what you were thinking?>>
The reason I ask is that I am hoping I can keep the refugium under the main tank on display but sump, pump, skimmer, etc.. would be on the other side of the wall in the room next door. <<Oh... sure. If you are taking the time to do a built-in with separate room, for certain.>>
Thanks and have a good weekend!!!
Den
<<You too. Cheers, J -- >>

Overflows and Refugium
Hello, I have a 120 gal tank with one overflow going to a sump with a mag drive 500gph. My question is can I add another overflow to go to a 10 gal refugium with a smaller pump or will it overflow.
<its not clear what you mean here? A second drilled hole overflowing to the refugium  but still draining to the main sump? If so, yes... will be fine. You mention another pump though? Does this mean a second pump returning the water back to the display from the refugium which acts instead like a second sump. If that's the case... no way, a danger. You best bet is to simply tap a refugium inline on the way down to the sump (or atop above the display and the refugium will overflow back in>
Also would a 36watt pc 50/50 be sufficient for a refugium with macro algae, live rock, polyps, and mushrooms?
<if said vessel was very shallow (12" or less). Anthony>

- Flow Dynamics -
<Hi, Bill, JasonC again...>
Hi guys a couple things that don't make sense to me in your return E-mail to me. I asked you how many overflow pipes you thought I would need to get around 4000 GPH from the overflow box to the sump your statement was <<How about this: for schedule 40 PVC 1.5" will give you 60 GPM, 2" will give you 150 GPM - you might want to consider 2" or larger for this application.>> What I don't get is you say a 2" will give me 150 GPM and a1.5" will give me 60 GPM. So that is saying that one 2"(150 GPM) will give me more than two 1.5" (60 GPM + 60 GPM = 120 GPM) What I'm thinking if I had 2-1.5" pipes that would be like having one 3" pipe. <It's really true - without digressing into a long discussion of physics and geometry, it has to do with induced drag and the actual area of the inside of that pipe... but it is in fact true - one 2" pipe can flow more water that two 1.5" pipes.> Something is not adding up right here. Could you explain to me how I will get more flow out of one 2" then I would get out of two 1.5"? <Not in this email - if you are really dying to know the answer, pick up the book Aquatic Systems Engineering by Pedro Ramon Escobar - the answers are all there.><<The surface area of a circle... pi R squared... do the math... 2" is more than twice the surface area than twice times 1.5"... RMF>> Also how did you derive at these numbers now this is siphon only no pressure (2"=150GPM &1.5" 60GPM) is there a formula or a chart (on siphon flow) that you got these numbers from?. <Those numbers reflect maximum flow, most likely under pressure which is going to be about as much as you can push through there. Again, pick up that book - it has all the math and related formulae in there.> You also state that I should go with a 2" or larger a 2"@150 GPM = 9000 GPH  I only need 4000 GPH. <More is better for this application. And really, the tank isn't going to overflow more than you are pumping in, with multiple 2" pipes you are just creating a margin for error.> Would I be better off going with a 1.5" and a 3/4" (1.5"@60GPM & 3/4" I'm guessing about 30 GPM=90 GPM=5400 GPH. <No, it doesn't make any sense to try and size things exactly - no room for mistakes.> Man ya need to be a rocket scientist to figure this out! <Not exactly.> You also stated(>In fact, the volume of your tank is large enough that overflow boxes would be unwise.>)
(WHY did you make this statement?) Isn't there thousands of people out there using overflow boxes. <On tanks much smaller, yes... and they still have large problems, which means with 650 gallons, your problems can/will be even larger.> I'm sure they all can't be having these problems with siphon tubes getting air in the tube and causing a disaster. Or am I just going about it the wrong way?<I think so, but this is my "opinion" - you're not obliged to listen to my advice at all.> The glass is bullet proof glass I was told I would be taking a big chance in drilling it some even told me it can't be drilled. If you think it is too risky for me to run a overflow box with a sump (believe me I don't want any floods she'll have me sleeping in the shed) <Oh, no doubt... as well as a potential insurance cancellation - no thanks.> I really want to get rid of this pain in the *** canister filter and fluidized bed filters. I'm also unable to use a Protein skimmer because the top of tank is to high off the floor 65" this is where a sump would come in handy. Do you know any other way I can make a better filtration system on this tank seeing you think my idea of a overflow box and sump is to risky? <Again, I would query around with knowledgeable glass people - many tanks of this size are drilled, and there is a good chance your glass is drillable too... probably not with the run-of-the-mill glass cutting kit, but it can be done. It will probably take a day or more, and you'll probably have to drain the tank, and house everyone elsewhere temporarily.> I hate to keep bugging ya about this but I sure could use your help. <No worries.>    
Thanks again guys.  Bill
<Cheers, J -- >

- More on the Dynamics of Overflow Boxes -
Jason Bill here again <Hi.> I promise I won't bug you again on this overflow deal could you please go to this site (http://atlas.csd.net/~cgadd/aqua/overflow.htm according to the plans on this overflow box if built and installed it correct way you should never have any problems with air getting in the overflow tubes or creating a siphon brake. Could you please take a look and let me know what you think. <Well, personally, I try not to use the word "never" - it's very final, and quite all inclusive. Will the person who designed this overflow buy you new carpet should the design that 'never fails', fail? All overflow boxes have a similar problem: the siphon tube. Likewise, it's not that overflow boxes don't work at all, but rather that they are prone to failure, and because Murphy's law will always reign supreme, it will happen when you aren't home. Personally, I don't trust overflow boxes of any type. If you are set on this solution, install double the number you think you might need as a redundancy measure so that if one or more fail, you'd still have some others to keep you from sleeping in the shed, and also keep the insurance wolves from your door.>
I do very much value your opinion. Thanks Bill
<Cheers, J -- >

- Plumbing the Overflow in a Small Tank -
To the experts, Please help I'm going nuts! I have searched the web site for hours and cannot resolve my plumbing problem. These are the basics. 30 gallon tank with a 10 gallon sump. DIY overflow (2 Lee's breeder boxes) 3/4 U pipe and 3/4 bulkhead fitting. 3/4 tubing down to sump. Return back to the tank is as follows: Mag 5 pump to 1/2 in. tubing to a Y fitting to 1/2 in. tubing to 1/2 in. 90's with Line lock fittings ending in the main tank. Now to the problem. I can't run the Mag 5 full open unless I remove the Durso stand pipe I've installed in the over flow. I have made 3 designs with the same results. All are design's from Mr. Durso's web site. All are based on 1 pipe size larger than the bulkhead, meaning they are constructed out of 1 in. pipe tee's, 90's etc. . I even made the straight 1 with out the Tee. All with the same results. Also can you help me out with flow rates with a 3/4 bulkhead and a 1in. bulkhead in my situation? <Hmm... think you are suffering from a couple of issues - first, I'm pretty sure the outlet of that pump is 1/2" which means that you are not restricting the pump when you use 1/2" plumbing which in turn means that the pump will perform at the rated flow. So onto the bulkhead - I think the maximum flow rate for a 3/4" bulkhead is 1,000 GPH, but not sure what the standpipe would do to change that - you might want to experiment by taking off the top of the Durso, so you just have a straight pipe, see how that runs with the pump wide open and then add the parts one by one until you find the limiting factor.> All help would be greatly appreciated, Thanks from a big fan.
<Cheers, J -- ><<The flow rate of this pump is too great for this system/drain pipe diameter to accommodate. RMF>>