stupid sump question

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Aquarium Advice Activist
May 30, 2008
evening all, this might be a really stupid question, but i will ask anyway.

iam adding a sump to my tank soon, the tank will be drilled at the top, just below water level. i have a eheim compact 5000 return pump.
here is the dumb part. how do you make sure that the flow from the tank though the drillled hole in to the sump is not to much for the return pump so the sump does not fill full, or vice versa that the return pump does not pump to much water back to the tank so it over flows the tank.

does that make sense.

cheers will
That depends on how large a hole you drill and what size plumbing you use. 1" PVC can handle 600gph flow. If you go larger it will handle more flow. You should try and match the pump to the overflow/drain. REmember you pump is going to loose some flow as it pumps water back to the top of the tank. Check out the flow ratings for your pump and go from there.
oh right,well the guy at the LFS is doing the drilling and pipe he should know what size hole to drill.

Maybe this calculator might help you to determine the flow rate upwards from standard pumps on the market. Its called "head loss", in that a 500 gph pump will pump less the higher up it has to go.

This "other site" also has a overflow hole calculator thing that might help also.

Reef Central Online Community
Moved to General Hardware and equipment discussion. And BTW the only stupid question is the one not aske. Thanks for asking. It was a good question.
I split the output of the pump one goes to the tank and one returns back to the sump. On both lines I have 2 ball valves and equalise the flow of the overflow flow and how much needs to go to tank and how much needs to return to not cause the sump to overflow or run dry.

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