must sump flow match skimmer pump rating


New member
My curve 5 pump is rated at 660 gph. Must sump flow exceed this?
Whatis the Down side of my DT overflow delivering less water?


New member
Noise. Bubbles. If your pump too big you might be able to dial it down with a valve on the return side. Personally, I see that as a bit of a waste.

You can do whatever you want. What I don't see here is what kind of overflow you have. full siphon with 1" pipe can easily handle 600 GPH. Mine does. No noise, either.

But there's more to it than the return pump and your sump. Overflow style, one or two drains, drain size and type, plumbing and how it's assembled etc. etc. etc.

But no. It doesn't HAVE to match - depends on what you want to do and your situation.


Space is big.
The downside is that the skimmer will clean up the water it is sitting in and stop producing skimmate while junk concentrates in the display and causes algae problems. What you really want is to have the chemistry of the water in the sump be the same as that of the display so that the skimmer can be as efficient as possible.


Grizzled & Cynical
Unless you go for absurdly low flow, I cannot see any reason why it's necessary to match return flow with the skimmer rating. In some ways a sump flow through lower than the skimmer rating turns it into a recirculator of sorts.


New member
hah - missed totally OP's question...duh.

It would be nice but not a complete necessity. If they are reasonably close it's good.

More about efficiency and sizing everything to work together really.

If the sump is a bit lower than skimmer output that MIGHT allow the skimmer to work a bit more efficiently as it will pass the water again in theory.

But would I put a 800 GPH skimmer with a 200 GPH return/sump design? Nope. Nor the other way around, either.

Close is fine. They will all work together much better and you'll get more consistent and expected results from your equipment.