What flow rate for 125 gallon display, 30 gallon sump, 16 gallon fuge?

20 20 · 09/18/2006, 08:57 AM

Yes, another "how much flow should I have" question.

Specs:
125 gallon display tank
30 gallon sump
16 gallon 'remote' fuge
ASM G3 skimmer
Closed loop with a Barracuda pump (4200 gph).

The pump I currently have is leaking, so I need a new one. Figured I check on opinions as to what the 'optimal' flow is through both the sump/skimmer, and through the fuge. Once I determine what flow rate I want, I'll pick out an external pump. Any opinions would be greatly appreciated!

PJSEA · 09/18/2006, 09:13 AM

What type/size overflow do you have and what size bulkheads?
Those factors will determine what kind of flow you can get.

I'm using a MAG 18 in setting up my 120 gal tank with 30 gal. sump. I have a 1.5" drain and 1" return and about 25" of linear overflow on my internal box. I expect to get somewhere around 1200-1400 gpm flow thru my sump.

sjm817 · 09/18/2006, 09:39 AM

You generally want about 3 -5x display volume. 375 - 625 GPH on a 125G tank.

20 20 · 09/18/2006, 11:17 AM

Two overflow drains, 1" each. I was expecting a number more in the 3 - 5x range for the sump, rather than the 10 - 11x a 1200 to 1400 gph flow would give me. That's why I'm asking, I know there are different opinions, just trying to find out the 'conventional wisdom'. Keep in mind I'll be running a closed loop that in itself will be giving me around 36x flow, so I don't need high flow from the return pump for 'total flow'. What flow is best for running by a skimmer, that's the question for the sump. Also, what flow should I be running through my remote fuge? Running it more for nutrient export, but a little 'pod production' couldn't hurt.

I would then add the desired flow rate for the sump to the desired flow rate for the fuge, and get a pump based on the combined total.

ChemE · 09/18/2006, 11:31 AM

sjm817 and I seem to post to a lot of these. I run 1.5x display volume and my skimmers have always worked fine. The real answer is however low you'd like as long as the surface of the display stays clear of the whitish film of surface active proteins which interferes with gas exchange. Not to say that 3-5x is wrong, but you may be able to use a smaller pump and use less electricity (good if you cool in the summer, less good if you heat in the winter anyway).

20 20 · 09/18/2006, 12:15 PM

1.5x, eh? Well, I do have a mag 7 sitting around that doesn't leak. Still need to figure out what kind of flow I should have through my fuge before I pick a pump.

09/18/2006, 08:57 AM	#1
20 20 Premium Member Join Date: Jun 2005 Location: Stewartstown, PA Posts: 1,246	What flow rate for 125 gallon display, 30 gallon sump, 16 gallon fuge? Yes, another "how much flow should I have" question. Specs: 125 gallon display tank 30 gallon sump 16 gallon 'remote' fuge ASM G3 skimmer Closed loop with a Barracuda pump (4200 gph). The pump I currently have is leaking, so I need a new one. Figured I check on opinions as to what the 'optimal' flow is through both the sump/skimmer, and through the fuge. Once I determine what flow rate I want, I'll pick out an external pump. Any opinions would be greatly appreciated! Last edited by 20 20; 09/18/2006 at 09:10 AM.

09/18/2006, 09:39 AM	#3
sjm817 On Yer left! Join Date: Sep 2004 Location: Northern VA Posts: 18,777	You generally want about 3 -5x display volume. 375 - 625 GPH on a 125G tank. __________________ - Scott

09/18/2006, 11:31 AM	#5
ChemE Registered Member Join Date: Aug 2005 Location: East Nashville, TN Posts: 1,607	sjm817 and I seem to post to a lot of these. I run 1.5x display volume and my skimmers have always worked fine. The real answer is however low you'd like as long as the surface of the display stays clear of the whitish film of surface active proteins which interferes with gas exchange. Not to say that 3-5x is wrong, but you may be able to use a smaller pump and use less electricity (good if you cool in the summer, less good if you heat in the winter anyway). __________________ Holding it down on the engineering tip y'all Current Tank Info: 190G

09/18/2006, 09:13 AM	#2
PJSEA Registered Member Join Date: Dec 2004 Location: Pawleys Island, SC Posts: 295	What type/size overflow do you have and what size bulkheads? Those factors will determine what kind of flow you can get. I'm using a MAG 18 in setting up my 120 gal tank with 30 gal. sump. I have a 1.5" drain and 1" return and about 25" of linear overflow on my internal box. I expect to get somewhere around 1200-1400 gpm flow thru my sump.

09/18/2006, 11:17 AM	#4
20 20 Premium Member Join Date: Jun 2005 Location: Stewartstown, PA Posts: 1,246	Two overflow drains, 1" each. I was expecting a number more in the 3 - 5x range for the sump, rather than the 10 - 11x a 1200 to 1400 gph flow would give me. That's why I'm asking, I know there are different opinions, just trying to find out the 'conventional wisdom'. Keep in mind I'll be running a closed loop that in itself will be giving me around 36x flow, so I don't need high flow from the return pump for 'total flow'. What flow is best for running by a skimmer, that's the question for the sump. Also, what flow should I be running through my remote fuge? Running it more for nutrient export, but a little 'pod production' couldn't hurt. I would then add the desired flow rate for the sump to the desired flow rate for the fuge, and get a pump based on the combined total.

09/18/2006, 12:15 PM	#6
20 20 Premium Member Join Date: Jun 2005 Location: Stewartstown, PA Posts: 1,246	1.5x, eh? Well, I do have a mag 7 sitting around that doesn't leak. Still need to figure out what kind of flow I should have through my fuge before I pick a pump.