What's the "rule of thumb" for return pumps?

[Fishnthecorner]

I heard the water should run through the sump at least 10 times per hour, so if i have a 240gal display tank, I need a 2400gph return pump? Do you count the sump volume too? Or does the space the live rock takes up, make up for the volume in the sump. It just seems excessive to go 10x!

[dlp211]

I don't think that is right. What you probably heard was that the water in your tank should turn over 10 times per hour. This means that between your return pump and powerheads/closed loop, your water should get cycled through 10 times.

Now this 'rule of thumb' changes based on what you are keeping in your tank, you'll need less flow for a FOWLR and more flow for SPS dominant.

You don't want the majority of your flow to come from your return pump, you want it to come from your powerheads/closed loop. Also if your sump has a fuge in it, you may want to slow your flow even more, at least to that portion.

I will end this by saying that there a million ways to be successful in this hobby and I am by no means a professional.

[Harriscli]

AGree on getting flow from both return as well as a closed loop/powerheads. You would need some massive drains to get 2400gph through your sump.

[reefereef]

I've always went by the 4-5x display turnover through sump.

[saleenpwr88]

I would try and match the GPH on your skimmer pump, that is really all you need going thru your sump IMO.

[96flstf]

Agree on the 4-5x as a starting point. Type of sump and skimmer could change this number slightly...

[rtparty]

3-5x through your sump is a good number to shoot for. If it is too fast, your skimmer won't be able to get the best contact time with a lot of the water.

For most tanks I think 20x turnover is a minimum to shoot for. I personally think FOWLR tanks should have a TON of flow to keep the food in suspension and so that poop is taken to the sump where it can be filtered out.

I think my nano cube is around 50x turnover right now and I can still turn my Vortech up if I need more flow.

On my 40g tank I ran an additional powerhead in my sump to help fight any stagnant areas down there as well.

[Rockhead21564]

+1RTparty
3-5x on return flow and min 20x on total with PH's/CLS. New build is a 300g that will have 13000gph tank flow, but only 1000gph return flow.

[Fishnthecorner]

Thanks guys. But a bit confused... I DO HAVE A FOWLR. It will be 235gal. So my current 1200gph pump (mag-drive1200) should be fine? It's on about a 4' head, so probably pushing about 800-900gph...

[Drae]

Slower flow thru your sump is preferable. Like stated before..skimmer pump and return pump should be matched up as close as possible, ime's it helps out the skimmer tremendously when contact time is maximized. Plus same thing with chaeto in your refugium

[rtparty]

Thanks guys. But a bit confused... I DO HAVE A FOWLR. It will be 235gal. So my current 1200gph pump (mag-drive1200) should be fine? It's on about a 4' head, so probably pushing about 800-900gph...

Yes, you are fine. Just make sure you have other powerheads in the tank for your primary flow.

A return pump is simply used to return water back to the tank, not provide your primary flow within the tank.

[SWSCJ]

Agree on the return and power head flow. Current 450 with additional 110 sump/refuge. 3200 GPH on the return and 3250 with the Koralia Mag #8. Probably 10xs total flow.