I have a 90 gallon tank with DIY sump filter. (DIY PVC
Overflow without box and trickle tower box in sump)
My Overflow pipe is 1" schedule 20 PVC
pipe and my pump is rated 440 GPH
(without considering height and bends). When I run the pump, the overflow opening is completely submerged under water. There is about 1" of water height above the opening of the overflow pipe. Is that normal?
I'm planning to put another overflow soon. But so far, it has been working fine except for the doubt listed above.