How much flow with return pump?

VashonBigs · Apr 1, 2020

Read a number of forums and people seem to disagree. Why not ask again? Have a 120G DT and another 30G in the sump. I have 1” dual returns. I’m running my COR20 pump at 100% and my returns drains are maybe 40-50% open at the valves to balance it. Should I be running this much water or slower? Pump temp seems fine?

Ron Reefman · Apr 2, 2020

That pump pushes 2000gph, right?

That's not too much flow for the main tank as it's only about 16 or 17 turns per hour. But the 30g sump is turning 66 times per hour. I think that's a lot. However, if it's just a sump and has no living things in it (no refugium) it's probably OK. But that would be way too much for a fuge.

mfinn · Apr 2, 2020

On my tanks I try and aim for 5x to 6x the tank volume through the sump.

ca1ore · Apr 2, 2020

COR20 max. flow is 2,000. Add plumbing and a bit of height and you are probably down to 1,500 … even less if you use locline. So probably at 10-12X. You don't say the size of the drains, but 40-50% seems fine. You can back off the pump if you want, but I see no particular reason to do so other than saving a bit of electricity.

Reefs and Geeks · Apr 2, 2020

No problem with the amount of flow you have. I prefer to run my return pumps at 90% or less just to help them last longer, but a good pump is designed to run at full power continuously for a long life already, so shouldn't matter too much either way.