Plumbing a siphon created when input doesn't equal output?


Bronze Supporter
Aug 30, 2016
Pittsburgh PA
On an equipment pad that is higher than the pool body....

If water volume on the supply side exceeds water volume on the return side, will the supply side drain backwards to the pool (more water weight)? I have 2 x 2" pipes on supply side and 1 x 2" pipe on return side.

I'm guessing it wouldn't if the returns are submerged (closed loop would only suck more water into the pipe). But what about water features that return above water (deck jets, water slide)?

I know a check valve would eliminate this so I guess it's more in theory.