Proper Flow thru the sump -- 11/16/2009
Hi, I have a 56 gal reef tank with a separate 30 gal refugium and 20-30 gal sump (sump and refugium located in the basement). In the 56 gal tank I have 2 powerheads( Tunze 6025=660gal/h and Vortech mp10 that I use it at low speed 500-600 gal/h). Could you suggest me how many gallons of water should flow thru my sump?
<Well, your flow needs will be met with the powerheads, so you don't need much through your sump. A few hundred gph up to about 600 will serve you well on this size sump. Consider what your overflow can truly handle, see:
http://wetwebmedia.com/BulkheadFloRateArt.htm.>
Thank you
<Welcome, Scott V.>

Refugium Water Flow 9/22/09
When I first learn about them a few years back slow gentle flow was recommended to allow the alga to remove nutrients. Is there a definitive water flow recommendation for refugiums?
<While some may argue still for slow flow through refugia, I do argue for more or at least supplemental flow within the refugium via a powerhead.
The reasons being: you do not want detritus to accumulate there either and Chaetomorpha is far and away the most common macro nowadays and it really should have enough flow to be turned (tumbled) a bit to allow the whole ball to be lit. The argument that slow flow is needed to let the macro absorb the nutrients is, well, false IMO. Plants do not work this way.
Even with higher flows the nitrate and other levels are what they are.>
Thanks!
<Welcome, Scott V.>

HOB Dual Filter Converted To Overflow To Sump-Possible? (Not with the two-pump balancing act described!) – 07/23/09
Howdy again most gracious Crew,
<<Hey Amy! Eric at your service>>
After 4 exhausting days of overflow boxes to sump research every corner of the known universe, I come to this basic question... What is the likelihood that I can balance two pumps (one to my 40g sump and one return to 150g display reef tank)?
<<Umm…not likely at all…at least for any length of time. Even with the use identical pumps (for reasons of operational likeness) and valves to initially “balance” flow betwixt the two pumps…detritus, bio-film buildup in the lines…heck, even gravity…will be working constantly to upset this balance. And you can surely imagine what would occur should a snail or similar critter/object clog/slow one of the pumps. My advice to you is to NOT attempt such an arrangement>>
Tank info: 150g, 175# Live rock, 100# live sand, HOB refugium, in-sump skimmer, 40g wet/dry sump, four Koralia #4 power heads, medium livestock load.
<<Whatever “medium” means [grin]>>
Living in AZ, we experience a lot of unexplained hick-ups in the power supply, usually lasting only from a few seconds to a few minutes,
<<Ah yes…I too experience such “flutters” (often the very abundant squirrel population BBQ’ing themselves on the transformers) in my power supply here in South Carolina. Many is the day I come home to tripped GFCIs or dimmed lights>>
but enough to make it hard to close my eyes at night or leave the house without constantly wondering if the return pump is going to stop while my conventional siphon overflow continues to empty my tank into my sump/living room!!
<<I assure you that your situation is not unique. I can also assure you that a little thought towards the configuration of the overflow will result in a system that will operate with a higher degree of safety and reliability than the “two pump balancing act” you are considering>>
After much obsessing and researching, I think that I could better live with the likelihood that both pumps stopped and started in unison if the power went out,
<<There’s no guarantee of this either>>
instead of trying to balance a conventional siphon overflow with a return pump, which IS going to cause an overflow here eventually.
<<Though I advocate drilling a tank and utilizing gravity overflows when possible (and even this method is not “foolproof” without thought to flow capacities and transient water volumes)…many, many hobbyists operate and get by just fine with siphon overflow systems>>
Also, could I convert a HOB dual filter into a power-driven overflow??
<<Not recommended>>
Understandably, it would move a lot less water than a large gravity feed but would still provide for continuous overflow to sump without worrying about an unexpected break in siphon.
<<I disagree that such a system is “without worry”…for the reasons already stated>>
I have seen the CPR self priming overflow but it has some design problems with clogging/blockages. I have two puffers who are messy eaters and I could foresee a blockage quickly occurring in my tank.
<<A pump could suffer the same fate then>>
How can sumps be both so wonderful and foolhardy at the same time???
<<A sump is a wonderful adjunct to a system, and getting water to/from it does require some thought, but is not an overly difficult task and certainly should not be cause for such agonizing as you seem to be experiencing. One solution that immediately comes to mind is to install “two” siphon overflows but utilize or adjust (with installed gate-valve) the pump to provide only enough flow as if you only had one overflow. This means both overflow systems are operating at “half capacity” which provides the redundancy for one to handle the flow (during your absence/until you are able to attend to the system) should the other clog or fail. Additionally, it is ideal that both the sump and the display be setup/configured to handle the “transient water volume” going either way in the event of a power outage/pump failure or siphon overflow failure>>
Thanks,
Amy
<<happy to share Amy… If you wish to discuss any of this further, please provide some detail of your overflow system re the type/configuration, the size and number of siphon tubes, the size/flow capacity of the return pump, etc. EricR>>

Re: HOB Dual Filter Converted To Overflow To Sump-Possible? (Not with the two-pump balancing act described!) – 07/25/09
Hi again Crew (Eric),
<<Hiya Amy>>
Please advise as to the best method of making sure that both the sump and the display be setup/configured to handle the “transient water volume” going either way in the event of a power outage/pump failure or siphon overflow failure. Should I first fill the display to max capacity, then work with the volume from there? Fill the sump to the volume/height needed for the equipment within (skimmer, etc.)?
<<Ah yes… This all takes a bit of experimentation with running/switching of the pump and overflow and watching how the water accumulates…being ready to turn on the pump/restart the overflow as/if needed. The idea is to have enough water in the sump for the ancillary gear present (skimmer, pump, etc.); yet leave enough “empty volume” to contain the transient water volume from the display when the return pump is not running. How much water volume “drains down” to the sump from the display when the pump is off is determined by the height (in this example) of the skimmer box on your siphon overflow. Adjusting this also lets you set the height of the water in the display, which will be a factor should the overflow fail and all the water in the sump gets pumped up to the display. Admittedly, this is of less concern to most hobbyists versus the need to contain transient water volume in a power/pump outage. And on systems with very large sumps versus displays, is often not even practical. But with your smallish sump (40g) and largish display (150g), you may be able to find/set a balance. So… Is all this clear?>>
Should I install two conventional siphon overflows,
<<Is the best option, yes…and as explained earlier>>
converging to a T,
<<No… Keep these separate. The idea is to not let them influence each others performance in any manner>>
followed by a ball valve,
<<I absolutely would not place any type of valve on the “drain” side of the overflow system. If flow needs to be tempered for any reason, place a gate-valve on the “output” side of the return pump>>
then going to the W/D sump. In the sump, water will be protein skimmed, refugium filtered, and then return to the display tank via pump.
<<Sounds fine>>
Should my return to display also have a T, with one going to display and the other a bleed-off back to sump for pump gph flow adjustment?
<<It is much easier to simply add the valve on output side of the pump, as described>>
Please advise, wise one.
<<Ah Grasshopper… I hope this all makes sense to you>>
Thanks,
Amy
<<Happy to share… Eric Russell>>

R2: HOB Dual Filter Converted To Overflow To Sump-Possible? (Not with the two-pump balancing act described!) – 07/26/09
Oh Eric, sadly, I am afraid we are at the point where I must confess that I earned a C in my fluid dynamics class.
<<Ah, no worries Amy…we’ll take it a step at a time if need be>>
Who knew I'd need it just to setup a fish tank??
<<Hee-hee!! Remember those “Why do I need to learn this?” questions we used to ask the teacher?>>
On to stupid question #128...
<<Only “stupid” if you don’t ask it… Okay, well…maybe not…but go ahead and ask anyways [grin]>>
So should I buy, say, two separate single bulkhead overflow boxes, each rated at 8oo gph (each containing a double set of siphon tubes) and just set them both to gravity feed approx. 1600 gph to my 40g sump (I know that they will actually flow much slower but lets just use these numbers for the purpose of setting ratios).
<<Yes to the first part…no to the second part. The idea here is to create a safety margin by setting up a “redundant” overflow. Buy/setup two identical siphon-overflow boxes, but only flow from the sump as much water as “one” can handle. Using your example/numbers…that would be two 800gph boxes with a max flow rate “from the sump pump” of only 800gph>>
OR should I buy one double bulkhead overflow box, rated at 1600 gph (containing a double set of siphons) instead?
<<I prefer “two separate” systems for redundancy. With only “one” overflow box, should it fail/lose water flow for whatever reason, it makes little difference how many “siphons” are present>>
These are some overflows I was looking at http://www.drsfostersmith.com/product/prod_display.cfm?pcatid=18358<http://www.drsfostersmith.com/product/prod_display.cfm?pcatid=18358> Will they work?
<<They will… And for purposes of figuring flow rates…Allow a “maximum” of 300gph for each 1” bulkhead drain and about 700gph for a 1.5” bulkhead drain>>
What size would be best?
<<With your smallish sump, I would go with a pair of the smallest here (PF-300) to ease any noise and bubble issues…and the use other methods (e.g. – powerheads) to create more flow within the display>>
In your infinite wisdom, you suggested <One solution that immediately comes to mind is to install “two” siphon overflows but utilize or adjust (with installed gate-valve) the pump to provide only enough flow as if you only had one overflow. This means both overflow systems are operating at “half capacity” which provides the redundancy for one to handle the flow (during your absence/until you are able to attend to the system) should the other clog or fail.>
<<Indeed>>
What will keep the overflows operating at half-capacity if they are just gravity fed? (Feel a migraine coming on...)
<<[grin]… Think about mate…if you have two overflows capable of handling 300gph each for a total of 600gph…but you are only pumping 300gph from the sump to the display…then essentially each overflow is only draining about 150gph (half-capacity). Thus… If one fails… The other will be able to handle the flow without flooding your floor. Understanzee?>>
Then from the sump, the water will be W/D filtered, protein skimmer, refuged, and then pumped back to my display. Then should the return be pumped by an external pump, to a T, with one line going to the display and the other a bleed-off re-circulating back to the sump?
<<I find “submersible” pumps to be entirely efficient (and cheaper and quieter) for most systems…and certainly so for yours. And “no” to the tee and bleed-off…not necessary. Simply install a gate-valve on the output-side of the pump to adjust flow as needed>>>>
Taking into account 5 vertical feet plus 3 90 degree turns on the line to the display and then 2 90 degree turns in the line to the bleed-off back to the sump, what size, brand etc. return pump would you recommend?
<<Figure a foot of additional head-loss for each turn/bend (but discount the two for the tee…as explained). So based on your data here you have about 8 feet of head-loss. Select a pump that can handle this plus an additional 20-30 percent to allow for mulm buildup in the plumbing lines as well as the…“unknown.” So, with two 300gph overflows; to be run at “half capacity” for a total of 300gph, plus an additional 20% capacity, you need a pump that will push “at least” 360gph at 8 feet of head. Not all pump manufacturers list flow rates at specific head heights (and who knows how accurate this is anyway), I suggest getting a pump that flows, at zero head, “about” twice what you think you need at your head height (some pumps are also more efficient at “pushing” water against head than others)...e.g. – we are looking for a pump that will flow around 720gph. Don’t worry if the pump may be a “little” big for your needs…the gate-valve installed on the output side will let you adjust the floe just hoe you need it. My first choice would be an Eheim pump (model 1262…though the 1260 would probably work)…but MagDrive (700 or 950) makes for a good second choice here as well>>
I am guessing that I will be pushing about 10-12 head feet with this setup. (Don't ask to see my math)
<<Actually, with your additional two ells for the bleed-off (which you don’t need)…that’s pretty close>>
Also, what size plumbing lines do you recommend I use for overflows to sump
<<Use lines at least as large in diameter as the bulkhead fitting…e.g. – 1” bulkhead = 1” drain line>>
and return from pump to display?
<<Match (or go slightly larger) the output on the pump>>
Sorry to ask so much and know so little.
<<No worries>>
You help is greatly appreciated!
<<Is my pleasure to assist. Do read here (if you haven’t already) and among the associated links: http://www.wetwebmedia.com/plumbingmarart.htm >>
Thanks again,
Amy
<<Be chatting… Eric Russell>>

R3: HOB Dual Filter Converted To Overflow To Sump-Possible? (Not with the two-pump balancing act described!) – 07/28/09
Hi Eric (with nerves of steel),
<<Hey Amy!>>
One last, well probably not the last, ignorant question... Forgive my retardation.
<<Hee-hee! You are forgiven…>>
You advised :
*<<Think about it mate…if you have two overflows capable of handling 300gph each for a total of 600gph…but you are only pumping 300gph from the sump to the display…then essentially each overflow is only draining about 150gph (half-capacity). Thus… If one fails… The other will be able to handle the flow without flooding your floor. Understanzee?>>*
NOzee! If I am dropping 600 gph (from two 300 gph overflow boxes) into a 40 g sump, and only pumping back 300 gph on my return to my display, am I NOT accumulating a surplus of about 300 gph in my sump, and on my floor??
<<Okay Amy…let’s break it down a bit. For the purpose of this explanation we’ll use the previous example and say you have two identical siphon overflows w/skimmer boxes installed on your system and each unit is capable of safely draining a maximum of 300gph…and… said skimmer boxes are set at the same height near the top of the tank (such positioning also sets the “height of the water column” within the display). Let’s also say you have a sump return pump that is pushing 300gph back up to the display. Now… As the display fills and begins to flow in to the primed skimmer boxes, water will begin to drain down to the sump. What you need to realize here is that with the skimmer boxes correctly positioned (e.g. – at the top of the water column in the display) the water volume draining to the sump cannot exceed that which is being pumped to the display. Thus… With two identical 300gph siphon overflow setups; positioned at the same height in the display…and a sump return pump pushing 300gph back up to the display…each overflow setup is essentially running at half capacity and providing the redundancy/margin of safety previously discussed>>
Yes, I know my display is only 150g and at some point in time, which I could probably calculate with high school algebra if I still retained any, the water level in the tank will drop down low enough to break siphon to the overflows.
<<Actually…no. The water held in the overflow’s skimmer box, though it will drain down a bit, should hold enough to maintain the siphon and allow things to “restart” once the pump is back on and flow returns>>
HOW do I make these overflows run at half capacity??
<<As just explained… By correctly positioning the skimmer boxes and only pumping as much water volume back up to the display as a single overflow can handle at maximum capacity>>
Aren't they just gravity fed and will each independently continue to drop the water down the PVC pipe into the bulkhead on top of the filter pad side of my sump (which by the way is only a single) at their 300 gph rate of flow??
<<Will only flow as much volume as they are “fed”…”up to” their maximum capacity>>
Maybe I should describe my sump. It is a Plexiglas box that has a fixed Plexi cover over the filtration side. The top has a single 1.5" bulkhead in the center. Below the bulkhead, the water falls down over a 12" x 12" filter pad (tray)
<<Do be sure to clean/replace this “pad” every couple of days…is a huge detritus trap>>
then down thru egg crate over about 14"H x 12"W x 12"D chamber of bio balls.
<<Do also research/read our thoughts on the use of this filtration medium in reef systems>>
Then the water flows horizontally through a series of baffles to be protein skimmed, refuged, and then pumped back to display. How should I plumb the two single overflows to go to my single bulkhead sump top?
<<I would recommend drilling a separate throughput for the second overflow drain>>
God bless you for enduring this ridiculous line of questioning.
<<Not ridiculous>>
You are a saint,
<<Hee! Others might disagree!>>
and this should probably be a paid position.
<<Your “understanding” here will be payment enough. And maybe the occasional WWM partially sponsored trip to the Big Island to do some diving with the Bobster [big grin]>><Let's go! RMF>
I really appreciate your patience.
Amy
<<Happy to share… EricR>>

Sump And Skimmer Problem 6/30/09
Hello and thank you for taking time to address my questions.
<Hello Roxanne>
I have several questions:
<OK>
1) I purchased a used aquarium set up. It is a 90 gal corner aquarium that is drilled for a sump. This is my first sump set up but I have been in the hobby for 10 plus years. My problem is that the sump drains faster than it fills. Now I am sure I am missing something obvious here, but for the life of my I can't get it to work properly. I have searched your site and found an article that seemed related, it talked about sump noise and that I should remove the bulb float valve. I did and had no reduction in noise (it got worse) and no impact on water movement. The drain hose is 1" and the return is ¾ .
<Typical, but are we talking about noise now or the sump problem?>
I am using a Rio3100 pump. It takes several hours for the chamber that houses the pump to drop significantly.
<How long is your return line? I'm guessing that the Rio is pumping water out to the tank slightly faster than the drain hose can supply. A one inch drain line is typically good for about 550gph provided no restrictions, bends/elbows, and gate/ball valves are used.
<<...>>
The chart below will give you an idea of what your pump will put out at a given head height. Again, this
is with no restrictions in the return line to the tank.
0" 1` 2` 3` 4` 6` (head height)
900 870 782 700 690 500 (gph)
As far as the gurgling/sump noise, using a Durso Stand Pipe generally takes care of this problem.
See here. http://www.dursostandpipes.com/>
2) My second question is, I need a new skimmer. Ideally I would like it to go under the tank either on or in the sump.
<You will sleep better at night if it's in the sump.>
My issue is that the initial chamber of my sump has a lid on it. The sump is acrylic and has 4 chambers. The initial chamber has a cover that allows for the drain hose to go right thru the lid, but this of course will impede my ability to put a skimmer in that chamber. I read your articles recommending raw water for
the sump, but I can't see a way to attach a sump <you do mean skimmer, correct?>
into this chamber, what is my next best alternative?
<Why not remove the lid if otherwise there is room for a skimmer.>
What skimmer would you recommend for this application?
<I would need to know how much room you have in the sump for a skimmer first, providing you're willing to remove the lid.>
3) Lastly, do I need a light in my sump? What are the advantages & disadvantages to keeping this area in the dark?
<Lighting is only used if the sump is configured as a refugium. Otherwise, no need to light.>
Thanks again for all your work on this site, it has become a site that I visit daily!!
<You're welcome. Sending a couple of pics along of your sump and overflow from the tank will help much here. James (Salty Dog)>
Roxanne

Here we go again.
Re: sump & skimmer problem..... 6/30/09
<How long is your return line? I'm guessing that the Rio is pumping water out to the tank slightly faster than the drain hose can supply. A one inch drain line is typically good for about 550gph provided no restrictions, bends/elbows, and gate/ball valves are used.
<<Hmmm, no, 300 gph max. safely, reliably and without noise. Please read http://wetwebmedia.com/SystemPIX/PlumbingPix/Oneinchart.htm
James, we have been over this time and time again. Please do take the time to actually measure this, you will be amazed!>>
As far as the gurgling/sump noise, using a Durso Stand Pipe generally takes care of this problem.
<<Not if the overflow capacity is being exceeded. Scott V.>>
See here. http://www.dursostandpipes.com/>
And for the actual quantified tests do see:
http://www.fishchannel.com/fish-magazines/freshwater-and-marine-aquarium/jul
y-2009/aquarium-bulkhead.aspx too! Scott V.
<Bob,
Sorry about that, too accustomed to seeing false advertising on flow rates of overflows, etc.
I do appreciate the link, just the chart I've been looking for.
Thanks,
James>
Hi Scott,
<Do you have any useful plumbing links you would like to share?
Thanks,
James (Salty)>
Re: Plumbing
I love the email format! Yes, I do: http://www.fishchannel.com/fish-magazines/freshwater-and-marine-aquarium/jul
, though it does look like you have seen it by now! Do realize these are the "best scenario" flows, hence the 300 per recommendation.
Scott V.

Tank Set Up, Return Pump and more 6/15/09
Hello Crew,
<Hello Henk.>
I am setting up a new tank, and am having it made according to following dimensions:
47.2*27.6*27.6 (120cm*70cm*70cm), about 150 gallon.
I chose for these dimensions because I will have a 10cm (4 inch) wooden trim at the bottom of the display tank, and a trim of about 5cm (2inch) on the top.
The bottom trim is meant to cover most part of the Deep Sand Bed in the display tank.
There will be an internal overflow box in the center at the back of the tank, with two standpipes of 2 inches.
The sump will be divided into 4 parts, with one part where the water enters, second compartment with skimmer and Ca reactor, third part actual sump with the return pump, and a fourth part will be a refugium with DSB and macro algae. The refugium will be fed with water directly coming from the display tank, with a means to control the water flow. Water from this refugium will then flow over into the part where the return pump is located.
<Just do be sure to run this restriction off of a T, allowing anything that is restricted by the valve to still continue on from the overflow line to other parts of the sump.>
I am planning to start out with some of the easier LPS, but would like over time to focus on SPS.
Now, for my questions... Regarding the return pump, I read on your site the determining factor for the size of the pump is the flow the overflow can handle, and I have not been able to find how much flow two 2 inch standpipes will be able to handle safely (and preferably without too much noise)?
<A single 2" internal diameter line will handle 1350 gph or so without issues....this does assume there are no horizontal runs in the overflow plumbing.>
Here in Beijing, the German Messner pond pumps are quite popular with reef keepers (seems to be the most widely used import return pump here), but I have not really been able to find any information on European or American message boards or websites regarding the use of these pumps in marine settings, so I am wondering whether or not these pumps are a good choice. I am not sure if you have heard of people using these pumps as return pumps?
<I have never used one, but these are submersible pumps, therefore no "saltwater seal" needed. You will be fine with one of these.>
As for the return into the display tank, I have the option for choosing either 2 or 4 returns, is 4 always better than 2?
<Not always, it can be too large/too many, diffuse flow too much.>
I plan to supplement circulation with 2 Tunze 6105 stream pumps and a multicontroller.
<Nice!>
I am just wondering if I choose 4 returns all located at the back of the tank, won't I have too much laminar flow, compared to when I would choose two returns pointed towards the sides of the tank, where the Tunze pumps will be located?
<Oh, no, just place them in the back. You can use PVC 45 deg elbows or a product called LocLine to direct the flow from each output.>
I am currently considering a return pump of about 2100gph. I assume there won't be much loss, the return pump only would need to pump about 5 feet up in a straight line, before either being divided over 2 or 4 returns.
<The loss is surprising, I would go with four 1/2" or two 3/4" returns for the flow you will end up with.>
Would you advise more flow through the sump, since the overflow might be able to handle more?
<No, this is plenty. Other issues arise, such as noise and micro bubble problems with too much flow through the sump.>
Finally, as to the lighting, if I want to keep my options open to have clams and grow SPS in the tank and not only at the top third of the tank.
Will two 150W metal halides suffice for a tank with this depth, or should I go for the 250W lights?
<250s if you want to be able to set stuff wherever you want.>
I have been reading and learning plenty from your website, and I hope I could run the above questions by you, since it is my first marine tank and people here in Beijing seem to implement a method of reefkeeping quite different from what is advocated on your website (usually with non-flood safe overflows, apparently no DSB tanks here at all, and heavy in-sump mechanical filtering with filter padding).
<Heee, too many people here too!>
Henk Naert
<Scott V.>

Tank Configuration 5/5/09
Hello All,
< Hello Ramon and Sons ! >
I have two questions that I need help with,
< Ahh, I thought you might. >
I have a Red Sea Max 65 Gallon All-in one( just cycling for about 2 weeks now) a 29 Gallon that has some Fiji rock 2 inch sand bed and a 10 Gallon tank that I am using to kill off BGA.
I would like to know which would be the best way to connect them all together?
< That would depend on your plans for each tank. >
I can't drill the RSM, 29 Gallon, or the 10 Gallon.
< Can't? >
I have 2 Maxi-Jets 1200s that I can use and buy an overflow for the 29 gallon to the 10 gallon and use the 2 pumps, one would be for the flow to the 29 gallon and one pump for the return from the 10 gallon to the RSM.
< O.K. If I am reading this correctly the plan is as follows:
The 65 gallon to the 29 gallon with a maxi -jet.
The 29gallon to the 10 gallon with an overflow.
The 10 gallon will then return to the 65 gallon with another Maxi-jet.
If drilling is absolutely not possible I would scrap the 10 gallon frag tank and have the 65 overflow into the 29 and then returned. The two Maxi-jets will not pump the same even if they are rated the same. Although
initially this could be corrected with the use of a valve, it is still a recipe for future disaster. You should also check the Maxi-jet with a head loss calculator to be sure it will be sufficient.
http://www.reefcentral.com/calc/hlc2.php >
I was thinking of making the RSM into a reef tank, the 29 gallon into a refugium and the 10 gallon into a Frag tank or do you have any suggestions on what to do with the 29 gallon and 10 gallon?
< You took the words right out of my mouth...or my keyboard. That would be my suggestion as well if drilling were possible. >
Any Ideas would be helpful.
< Please write back if you decide to drill and/or have anymore questions >
Thanks, Ramon and Sons
< You are quite welcome. G A Jenkins >

Re: Tank configuration 5/6/09
Hello Again,
< Hello! >
Thanks for the reply.
< You are welcome. Just trying to be helpful. >
I wanted to let you know that I was going to try the overflow method with the RSM 250 (65 Gallon) to the 29 Gallon
< Great! >
The only thing is, I have two concerns and they are :
1. I want to keep it as a display tank (maybe a refugium with some nice looking micro algae) which it is now
< Sounds very nice. There are a lot of options available for a display 'fuge. Seagrasses ,macros, etc. .. Your imagination and wallet being the only limits. >
2. it is set-up about a foot away from the RSM. As of now I have 3 fish in the 29 gallon that is why I can't drill the tank.
< I can't say that this is a real problem. If you really want to drill the 29 you can move 10 gallons of water and the fish to the 10 gallon while you drill. You could also just put a frag rack in the back of the 29 and
call it a day. Either will work but the 65 gallon reef to the 29 sounds display refugium sounds like a winner. The tank being a foot away also shouldn't be a problem as long as your return pump is rated high enough. G
A Jenkins >
Ramon Ortiz

Sump design/internal overflow 4/20/09
Hi all,
<Hello.>
I 've got a situation here. I have a 55 gal Truvu acrylic main tank and want to plumb in a 55 gal sump in my basement about 10' below the main. Now I was just given a Calp4200 return pump which has a flow rate of 4200gph at 0 head. By putting the sump set-up in the basement it reduces the gph to around 2500gph because of the 10' return distance between the two tanks. My idea is to build a internal overflow but don't know how big and I need to know if 2 /1.5" bulkheads will work for drainage.
<You will need dual 2" drains for this flow....more to add some redundancy.>
I also want to add at least 8 3/4" returns four in the back of the tank and four in the bottom all drilled for 3/4" bulkheads. I basically need some advice on how to use this pump in relation to the ideas I listed.
<If you want 8 returns I would go with 1/2" for this flow. Also be weary of putting return lines through the bottom or too low in the back. When the pump is off it will drain/siphon water into the sump. Many people do this and rely on check valves. A check valve WILL fail sooner rather than later in this application; there is just too much in marine aquaria that will end up propping the valve open. Scott V.>

Re: Cyanobacteria/BGA/Sump Return Pump 4/9/09
Hello Scott,
<Matt.>
Do GenX, Iwaki, & PanWorld Pumps in the 1100-1500gph range generally have the same 1" inlet height alignment?
<Generally close enough to "get by".>
Is there some kind of standard to that?
<No.>
I have been switching out pumps to try and get one that is quiet and powerful. So far I tried the Iwaki 70RLT with too much noise, then swapped to a GenX1100gph with a slight improvement but still not quiet enough for the family.
<I bet, big powerful pumps with big powerful noise.>
Then I stumbled across good reviews "quiet & smooth" comments about the PanWorld pumps. I only get a little concerned with height settings as I already have a sump hole drilled for 1", the first 2 pumps aligned ok....not sure if the PanWorld will align... do you know if these are quiet running pumps?
<Generally considered so, but they do still produce some noise. If you are going to run a largish external pump there are a few things you can do to help this out. Set the pump on some vibration dampening material such as a silicone pad...McMaster.com has many options. Also, plumbing the pump with flexible PVC can help.>
The GenX and Iwaki have loud fans on them, hoping for better with these Panworlds for this and future tank setups if you have any experience with them?...
<I do, and although I do feel they are quiet for what they are, they are still not without a certain amount of noise....don't look for a huge difference. For what you are doing here I would look at the Poseidon PS4. They are essentially water cooled rather than fan cooled. This does keep the noise down, but does heat up the water a bit more.>
Thanks again,
Matthew
<Welcome, if you want to try the PanWorld the manufacture's site has a detailed diagram for the input height: http://www.panworldamericas.com/PS/Inch/B1202554.pdf
Scott V.>

Re: Cyanobacteria/BGA/Sump Return Pump 4/10/09
Yeah I've got a PS4 on standby if the PanWorld is too loud for these folks. The only thing I don't like about the ps4 is that they don't have enough pressure on them to move enough water esp. when going through a 1" SCWD and check valve w/ a few 90's along the way and for a 110 gallon 5ft tank...it also has 3/4" in/out and would need riser/padding underneath to align with sump. Great pump for smaller tanks with chillers, I've got one on my 75 as the return pump, but I had to get a Vortech to get enough flow in that tank. So im hesitant on using the PS4 if I can get away with the PanWorld.
<Ah, ok!>
Some have said it's a hit or miss with individual pumps, some work well, others of the same model sounds like s***...I wish someone would develop a quiet 1" size pump with minimal heat transfer.
<Me too. There is a gap in the pump world between fairly efficient and quiet submersible types for a few hundred gallons of flow and the large Reeflo type pumps. If you want 1000-1500 gph of flow it leaves few options.>
-Matthew
<Do let us know what you think of the PanWorld comparison....like you said sometimes it comes down to the individual pump. Scott V.>

Re: Cyanobacteria/BGA/Sump Return Pump 4/10/09
Hey,
I installed the PanWorld pump...this thing works wonders man. It's about 95% as good as a Reeflo dart as far as noise goes. Silent operation.
<Wow, good news...I have not used on in a while.>
That GenX and Iwaki pump i had tested were ridiculous compared to this new PanWorld.
<Good to know, thank you for sharing here. This will help countless others in the future.>
-Matthew
<Scott V.>

Plumbing: Adding second sump inline to first. 3/12/2009
Hello Team,
<Hi Rylan>
Thanks in advance for your time. I have a 75 gallon FOWLR with a 29 gallon sump underneath. I currently have 90 lbs of rock in the tank and 5 lbs rubble in the sump with macro algae. With water displacement from the rock, and the fact that the sump only holds 20 gallons when "full," My entire system is probably 85 gallons.
<Sounds about right.>
Knowing that higher water volume is inherently more stable than less and that increased water volume diffuses the bio-load better than less, logic tells me that plumbing a 96 gallon Rubbermaid container to serve as a "bladder" would do nothing but good things for my water parameters.
<It would make the system more stable, larger water volume to dilute any pollutants.>
I would take the overflow plumbing that is currently going from the tank into the sump and redirect that into the 96 gallon container. I would drill a drain hole roughly ¾ of the way to the top so that the water would then cascade (through plumbing) to the sump, where it would continue as normal to the return pump. It seems that this easy addition would greatly increase the water volume in my system (a good thing). Since I know you guys have tried everything once, can you tell me if there are flaws in my thinking? As this is a theoretical discussion, I didn't include water parameters or livestock details.
<What you are proposing is logically sound provided you take some precautions. My apologies, but there will be math involved....:-)
Your discharge hose from the Rubbermaid sump MUST be placed high enough so that in the event of a power\pump failure, the volume of water that will continue to drain from the tank by gravity PLUS the volume of the Rubbermaid container from the bottom of the discharge pipe to the water level in the container PLUS the volume of water in the plumbing MUST be less than or equal to the maximum safe water level in your sump.
As an example, if your sump can safely hold an additional 10 gallons of water before it overflows, and your tank will drain 5 gallons of water under gravity, and your pipes will hold 2 gallons of water, your discharge hose from the Rubbermaid container should be placed so only two gallons can drain out if pumping stops.>
Best,
<Do let me know how it turns out.>
Rylan
<Mike>

Plumbing conundrum 3/1/09
Hi,
<Hello Peter>
My (FOWLR) main tank is 52x18x22 with sump directly underneath 48x15x18
If my total is 580 litres, (120gl) turnover required to turn 8x the volume would be about 4,640 l/h 960gph (I think).
<Should be shooting for 10x combined flow rate including powerheads.>
I shall have two 1 inch pipes running from my sump pump, back up to my tank. I have read that the pipe diameter governs that they can only allow 1,000 l/h through each pipe back to my tank. This would leave me needing 2,640 l/h turnover from my powerheads to turn 8x the volume. Is this correct?
<Will all depend on restrictions to flow such as use of elbows, valves, length of pipe, etc, but the flow rate will always be lower than
the rated flow of the pump. The 130cm converts to 51 inches (my way of thinking) and that alone is going to reduce the flow quite a bit. The maximum head for this pump is 10.5 feet and you are using close to half of that.>
I was going to buy the Ocean Runner 3500 but now think this will be to much through the 1 inch pipes. The height from bottom of sump up to main tank is 130cm & plumbing is a simple vertical straight up & down with no 90% bends. Would I be better going for the Ocean Runner 2500.
<I'd stick with the 3500, will not be too much. The 900gph flow rate is going to be divided between two 1" returns and you will need a "T" somewhere to do this and it will further reduce the flow rate. You likely will only be getting around 200-250 gph from each return considering the "T" and the 51 inch head.>
Also for a tank of this size how many and what size should I use of the Hydor Koralia powerheads. I thought 2x Koralia 2 powerheads would not be too turbulent.
<I believe the two Koralia 2's will be just fine combined with the Ocean Runner 3500. These are stream type pumps so you will not get the jet effect. I'm using a Koralia 3 in a 60" tank and it does move a lot of water. Two of these in my tank would be too much. Keep in mind that the Koralia pumps are not designed for Wavemaking devices. If this is desired, you will need to go with the low voltage Koralia's and use their Wavemaking device.>
Thanks for your time & help.
<You're welcome. James (Salty Dog)>
Peter

Re: Flow and Pump Question 2/28/09   3/1/09 
Scott,
<Hey Randy.>
Thanks for the response and info, but I'm still a bit unsure on the pump size. I have some telling me that the OR2500 will be good for the two 1-1/4 ribbed pool hose lines/drains(running only 10" into sock) from the Megaflow box into the sump and others that say it's not enough.
<It is, do realize that most do not recognize that running overflow lines to their limit is a recipe for disaster.>
I also hear that the OR 3500 is way to much and I will need to dial it back on the return, also people say that it's to much flow thru the sump???
<Hmmm, it can be managed through the sump, but the lines will not handle the flow.>
I am waiting to order my return pump based on these issues? Any more advise will be greatly appreciated!!
<The OR 2500 is my “go to” pump in most applications. Price, reliability and the flow capacity of many setups line up well with this pump.>
I am also contemplating on not using the 300 micron filter sock, is it a big help in the full reef. I know it needs attention weekly but I will probably only get to it every 2-3 weeks. Will this be a big issue with the nitrites?
<It can be…just buy a half dozen or so of the socks (they are comparatively cheap) and swap it every few days. Then just wash the whole lot at once. This make maintenance quick and easy and keeps the nitrate factory to a minimum.>
And I have decided to go with the Extreme pro T5's(6bulb) over the Tek for mostly cost reasons and the additional size of the Tek.
Thanks again,
Randy
<Welcome.>

Sump Design 2/25/09
Hello,
<Wes.>
I've been spending quite a bit of time reading the helpful insights that you have on your site. Excellent!!
<Thank you.>
I have a new system. 75 gallon sump. Will have it plumbed to 2 tanks. One sump pump for each tank.
I have the option of 3 or more drain lines going to different parts of the sump. I will have a collection sock sleeve followed by a small wet/dry Bioball chamber at one end,. Next to it will be about 50lbs of Live Rock and a protein skimmer.
Then the water will pass through baffles for a small refugium area and finally overflow into the area with the 2 pumps.
My question is this: Will this be too much circulation through the fuge?
Should I have one of the drain lines go straight to the Pump area to lessen the flow?
<How much flow, what sized lines and what size refugium are we looking at here? See: http://www.wetwebmedia.com/sumpdesfaq.htm>
Thanks
Wes
<Welcome, Scott V.>

Reading through, typo city, resent corrected version. Scott V.
Re: Sump Design 2/27/08
Hello Scott,
<Hi there Wes.>
That was a fast response!
<We try our best to be prompt.>
Regarding the 75 gal sump.
The sump will have approximately 1300+ gph flow coming in from the drains. The 2 pumps are rated to push that much up the 6.5 feet returns, {this is after a minus of an estimate for drag from elbows, unions, valves, etc.}
There will be 2 return lines planned to go into the sock sleeve.
The return lines will be 1 1.5 drain and 1 1" flex hose drain.
<As in a 1” and a 1.5” overflow drain? Those will not handle 1300 gph.>
I should be able to baffle off an 18x12" section for the refugium.
<Ahh, good.>
Alternately I could have another 1.5" drain go straight to the Pump section of the sump {this would draw about 300-400+gph from the main drain line.
<I would do this, two 1.5” drains along with a 1” will give you about 1800 gph in overflow capacity….better to have more than less here. If you are still at the drilling stage do consider two 2” drains, this boosts you’re your number to 2500-2600 gph capacity. This leaves you some redundancy should one line fail.>
thoughts?
<Above.>
thanks
Wes
<Welcome.>

Power outage overflow   2/3/09
Hello. Thank you for all the great information on your site.
<Happy it has helped.>
I have a question regarding power outages and sumps. I have searched my question, but have not seen exactly the solution my husband is trying to use. We are currently setting up (slowly and methodically) a 150 gal. FOWLR tank with a 50 gal. sump. That is all set, plumbed, and running. In order to prevent a flood in case of a power outage when we are not home, he wants to put a bulkhead at the top of the sump (above the normal water level) with piping running out the door, which we could easily do and hide since this set up is in a basement room. What do you think?
<It will work, but will of course require the sump be topped off when the power returns. Check out
http://www.wetwebmedia.com/sumpdesf8.htm too. James Gasta has a similar solution here.>
(and as an aside, thank you for promoting readable messages and grammar on your site - I am an English teacher who spends her days consistently appalled by errors).
<Heee, happy to hear from those who appreciate it! Scott V.>

Which return pump? 1/23/08
I was starting a 75 gallon marine tank, I just bought a cpr cs102 overflow that does 1200 GPH. I was planning on buying a MAG drive 9.5 I figured with about 3 feet from sump to overflow and using 1 90 elbow that my flow from
the return pump should be about 800 GPH is this the right pump or should I get a pump that does more.
<The 9.5 is a good choice. You will not have 800 GPH at the tank from it, but the overflow will not handle 1200 gph either! It is just purely limited by the bulkhead size on the backend! See:
http://www.wetwebmedia.com/SystemPIX/PlumbingPix/Oneinchart.htm
The 9.5 will be just right for this.>
Thanks for you time and answer.
<Welcome.>
Sorry if you have already answered this I have researched pumps and overflows and it is a bit confusing to me.
<Do consider a second one of these overflows. Should one fail the other will keep the water off your floor! See:
http://www.wetwebmedia.com/overfloboxfaqs.htm
Scott V.>

Re: Which return pump? 1/23/08
Thanks, I'm glad I read that article I'm about to get a 240 reef ready, surely they would make them bigger then one inch, but I'm going to make sure.
<You will likely be surprised, most are 1"!>
Thanks for the good information.
<Welcome, Scott V.>

Head Height and Return Pumps   ~ 01/12/09
Hello Everyone.
Always a Great Help.
<Hello Frank, thank you.>
I am currently setting up a 110G 5' long tank that has one overflow box within the tank. I bought this tank used. It had a 1inch bulkhead for the drain and has 3 1/2inch bulkheads on the tank sides for the returns.
I drilled a bigger hole to accept a 2inch bulkhead for the drain.
<A great move!>
I have a 50G tank that I will be using as the sump. I as using 3 Pentair Quiet One 2200 (rated at 581gph) pumps as the return. I am looking at approx 4' head height on two of the returns and approx. 6' head height on the other return. My question is this: Will 1/2inch sized bulkheads be adequate for the pumps to return the max flow they're capable of with that height or will they restrict, or should I enlarge them to 3/4inch or 1inch?
<I like to run 250-300 gph through a 1/2" return. It leaves a good flow without blasting anything. Considering what head you will have on the pump you will be just about right with the returns you have.>
Thank you for your assistance.
Frank
<Welcome, Scott V.> 

Reef/ sump plumbing and Stocking question 12/2/08
Hello all,
<Hello Randy.>
I have a few plumbing and stocking questions.
First the plumbing questions. I am setting up a 72 bow reef with a 30 gallon (36") custom sump below. The sump will contain a twin sump inlet assembly with 1-300 micron bag, 1 -ASM G3 skimmer, 4 over/under baffles and then a 10x12x13 return pump area. I will be drilling the tank and adding www.glass-holes.com's in tank overflow kit. With the sump there should be aprox 90 gallons of water(80 with rock added-guessing??). I will be adding a 3/4"SCWD on the return for varied output flow. And there will be a Hydro Koralia #3 in tank powerhead. Is the Mag return w/SCWD and 1 Koralia going to be enough flow? Should I add a second Koralia #3?
<I would, you will not have too much through the return with the Mag and the SCWD combined. You will have a more balanced flow with the extra powerhead.>
I know there is no such thing as too much flow (within reason).
<The application of the flow is just as important. Random, not laminar.>
With this said, should I go with 2- 1" lines into my sump or 2- 1.5" lines into the sump?
<Definitely the 1.5" lines, you do not want to restrict the overflow drains.>
If I go with the 2 1.5" lines and the 3/4 "Y" setup on the SCWD which MAG pump do you recommend? The MAG7.5 or 9.5??
<The larger will still leave you redundancy in the overflow once head and plumbing are accounted for. I would go for the 9.5.>
I would like to get it matched as close as possible. I have heard that using a partially closed valve on the return side (or any side) can cause potential blockage over time as debris accumulates.
<If you are referring to the overflow, do not restrict at all! As for the pump, you can restrict the output if need be, you will not need to here.>
If I use the 2- 1.5" feeds, should I step up to 1" returns from the MAG to the SCWD(I believe that both devices have 3/4" male NPT fittings), and then 3/4" from the SCWD to the tank.
<Little to nothing to gain over the ¾" for the run it will have.>
I am thinking about drilling the returns and using bulkheads, what is your thoughts on this? Any issues, advise?
<You can IF you have sufficient transit volume in the sump, the amount of water that will drain or siphon into the sump when the return pump is off. Otherwise, just plumbing it over the top to a length of LocLine allows you to place the return just below the water's surface, minimizing this volume.>
Also, is the ASM G3 skimmer to big for only the 80 gallons of water?
<No, a fine size for this system.>
Will it over skim?
<I'm not a believer within reason.>
Should I put it on a time, for how long? I had it on my 120 and loved it for skimmate collection.
<Just let it run and collect nasties.>
Now for the stocking. Can you tell me the best tang for a disease free reef tank? I am leaning toward either a purple or a yellow eye/Kole?? Do you think that these fish will work together?
<I would stick with just the Ctenochaetus strigosus in this size tank.>
I know I'm at max. Currently have-1 yellow watchman, 1 Ocelers. clown, 2 yellow tail damsels---Would like to add, a ick resistant tang, 1 midas blenny (will he work with the watchman?),
<Chances are good they will clash.>
2 neon gobies, 1 royal gramma, 1 flasher or fairy wrasse, 1 six line wrasse,
<Be aware these can be bullies and put any shrimp in your tank at risk.>
and possibly a pair of Banggai cardinal fish.
Do you have a preferred flasher or fairy wrasse that is recommended for price, availability, and beauty?
<Cirrhilabrus rubriventralis in my book. Do be sure to cover the tank for any of these wrasses, they are jumpers.>
Thanks for your time and devotion to our hobby,
Randy
<Welcome and thank you, Scott V.>

Re: Max Sump Flow Capacity and Overflow Redundancy 11/21/08
Thanks a ton for the advice Scott.
<My pleasure.>
Hopefully I'll be able to leave you alone for a while after this one. I'm pretty sure I won't be able to design the sump and plumbing in a way that allows the drainage to flow at the "ideal" rate into each of my sump's chambers (skimmer and 'fuge) right off the bat. I think the ability to adjust the flow to each chamber after setup will make my life easier.
<Agreed.>
I'd also like to adhere to your recommendation of 100% overflow redundancy.
<Good.>
Attached is my attempt at achieving both objectives with the plumbing, but I apologize for my horrible artistry.
<Tis better than mine!>
Would it be better to use a 3-way diverter<http://www.westsidewholesale.com/index.cgi?pid=975570&CATEGORY=70321&source=ad3>at
location "A", or ball/gate valve at location "B" to control how much from each overflow goes to each chamber? Or, do you have a whole different idea on how best to achieve this?
<Go with the gate valve option. The problem with a three way is that it will restrict both outputs to some extent unless one is fully open and the other closed. This reduces flow quite significantly on these gravity fed drains. A gate valve placed below a T fitting will allow one of the outputs to always be fully open.>
Any other improvements you might recommend would be fantastic.
<Looks good.>
And if I might shake more piece of fruit from the tree, do you happen to know which skimmer combo would be the quietest? EV-120 with Mag 5, EV-120 with Eheim 1262, or Euro-Reef RS100 with SEDRA KSP-3500A.
<All will be reasonably quiet, the 120 with the Eheim will get my nod.>
Thanks a lot!
<Welcome, have fun setting up. Scott V.>

Need an Expert Opinion--Sump/Overflow  10/20/08
Greetings,
<Jason.>
First I can't say enough about your website, it truly is a gift.
<Thank you.>
So, I have a 60 gallon FOWLR with only a few fish (mated tomato clowns and a blue damsel). Also have plenty of live rock (don't know how to estimate weight) and about a 3-4" deep sand bed. Currently I have 2 Hydor Koralia's for circulation along with a BAK-PAK 2R protein skimmer and a CPR Hang on Refugium. My wife and I are looking for a "more attractive" solution. So we've purchased a CPR CY 192 sump/skimmer. Our tank isn't pre-drilled. So, I’ve purchased 2 300gph Eshopps overflows to flow into the sump via a T into the sump. Then I have a Mag Drive 7 to pump back into the main tank. I guess my question is, what is the appropriate way to set up the flow so that my overflow boxes are truly redundant?
<Limit the flow of your pump to what one of these overflows can handle, leaving the capacity of the second for “just in case”.>
For example, if one goes out, how do I make sure the other one can pick up the slack without overflowing.
<Limit the return to 300 gph.>
Another question, and this one may be stupid, with two 300gph overflows is the effect additive, so the resultant would be 600gph?
<Yes, at a maximum.>
I know it may not be exactly that given resistance in the pipes, etc. Any other criticism or ideas/modifications would be helpful. I know that no overflow system is 100% safe and that regular maintenance will be needed to keep it running to it's best. So I’m looking for a "safe as can be" system.
<A drilled tank is safer, but if you do limit the flow and keep one overflow as a backup you will be fine here.>
Thanks and keep up the good work.
<Will do, thank you.>
Jason
Wake Forest, NC
<Scott V. Fresno, Ca.>

Max Sump Flow Capacity and Overflow Redundancy 11/18/08
Hi Crew,
<Hello.>
In my quest to build my perfect sump, I'm now having a hard time calculating how much flow I should be sending through it.
<Okay, worthwhile quest.>
I've designed my 70g tank with two 1.5" overflows, which I've read have a 600gph maximum capacity each.
<A little more than 700 per, you are on the safe side.>
I've figured I've got room for a 30g sump in the tank's cabinet. I'm planning on splitting the drainage between the skimmer and 'fuge chambers, both flowing into the middle return chamber.
I'm planning on using an EV-120 skimmer (or an Eshopps PSK-150, opinions?),
<The AquaC for me.>
and growing Gracilaria in the 'fuge. With your vast experience, would you think a return pushing 600gph (after head loss) into the tank would overpower either the skimmer or 'fuge chambers?
<This is a reasonable, manageable flow.>
I'll be using a bleed valve to control the return pump's output, but don't want to buy a much larger pump than I'll need.
<A ball valve on the pump output to throttle it back if you have too much flow is all you will need.>
The pump's noise level is a great concern, and I'm reading good things about the Eheim 1262 (and will be using a mouse pad underneath).
<As quiet as pump comes.>
I'm also wondering just how much redundancy is reasonable in my overflow plumbing to prevent a divorce :)
<100%, if not more.>
When an overflow fails, does it usually do so (clog) at the inlet?
Anywhere specifically in the plumbing?
<There are few ways for a 1.5" gravity drain to fail. Usually something covering/plugging the inlet. I
have had the misfortune (stupidity really) of floating bags that smother the overflow! Other possibilities
are snails, algae, dead fish, etc.>
I'm basically wondering if plumbing each overflow completely independently into each sump chamber is recommended or overkill?
<I would, it is not overkill.>
Maybe just join the two 1.5"drains into a 3" just as they exit the display tank?
<Go with the two independent lines. With 600 gph of flow, either of your drains can handle the job without the other. You will be in good shape.>
Thanks very much for your time, and in helping me learn from your experience!
<Very welcome, Scott V.>

Sump/Refugium Flow Rate Question 10/4/08
I am in the process of setting up a 300 gal. tank with a separate three compartment sump/refugium.  I am still in the planning stages (actually, I only have the tank so far) and have read a lot about the benefits of a refugium and DSB. 
<Many, definitely worth doing.>
My plan is to build a 55 gal  baffled refugium (L 60” x  H 18; x W18; with ~12; high baffles) with the middle 24; being the refugium with a 5; DSB.; Since the tank has duel overflows/returns, I am planning to run two;Iwaki MD40RLXT pumps for the return. 
<Are these the typical prebuilt overflows? If so do read http://www.wetwebmedia.com/ovrflowboxfaq4.htm and the linked files. The industry’s “reef ready” tanks are rather disappointing in overflow capabilities for the most part.>
These pumps are rate at 1,200 gph which, I assume, will translate to about 2,000 gph after normal power loss due to the trip to the tank.  My question is if this rate of flow will be too much for a refugium in which I hope to keep some pods, macroalgae, cleaners etc? 
<No, this will be fine for this size and volume. The livestock can handle it.>
If so, do you have any thoughts on a better way to do this?
<You could run your skimmer and refugium compartments on opposite ends, with each overflowing into a middle pump return compartment. This will allow the refugium to see only half the flow, although I would not worry too much about this criteria. The main advantage to this configuration is that it allows you to increase the water level (and volume) in the refugium area. The downside is a bit tougher plumbing with two external return pumps.>
Thanks,
Michael
<Welcome, Scott V.>

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