Yea it could be the head pressure of the return pump the more it has to push the water the less it's going to pump.Is there away to change where the evaporation happens in the sump? I want to if its possible to rearrange my sump that the area that water evaporates and gets filed from ato is not the same place my return pump sits. I tried some google searches but not really sure how to explain it in away google understand LOL. The change in the height of water in the return chamber is what I think is the cause of the water level changing in the overflow. Not having as bad of an issue as I was having now that the flow has been slowed down, but I dont want to run like this if I dont have to. As the water evaporates and ato kicks on raising the water line. The overflow box water level moves up and down very slowly. But by evening time the evaporation slows and the ato stops filling. Hours after all this has happened the water level equal out eventually and that height is either low and makes noise In overflow or its high ano goes down the emergency drain. Its a back and forth, back and forth torn in my side.







