Overflow not big enough

[valles]

Hey guys I am having an issue with the water in my sump getting low real fast and not do to evaporation. I have a 90 gallon tank with a 1600 gph return pump turned all the way down and an overflow rated at 800 gph. The overflow has 2 exits so what I did I joined the 2 and made it into one since my sump only has one connection for a pipe do you guys think since I joined the 2 exits of the overflow it dropped it to about half the gph and that's why the water in the sump drops quickly?

 

[lmforbis]

It will definitely affect the flow if you connect them. You can increase your total water volume in the system, slowly though. Do you have a gate valve on your return plumbing. That is the best way to control the flow.

 

[valles]

It will definitely affect the flow if you connect them. You can increase your total water volume in the system, slowly though. Do you have a gate valve on your return plumbing. That is the best way to control the flow.

No no valve on return pump I do on the overflow tho.

 

[lmforbis]

You do not want a valve on the over flow. It should be wide open. You need a valve on the return so you can control the return flow which in turn dictates the overflow.

 

[beaslbob]

+1

The overflow should have no valve and be basically a straight through pipe to the sump. Whatever is returning to the tank should overflow to the sump. no valve/adjustment necessary.

perhaps a picture would help.

 

[2quills]

Unless you up-sized the drain pipe and connection where they are tied in together then it sounds like you effectively reduced the drain capability by half.

Agree with the others recommendations about the valve on the return line.