BeanMachine
Active member
I do not use check valves. I've always thought if you have to use a check valve you are doing it wrong. They will fail. I always build my systems so the returns are up high they can only siphon back a certain amount of water and not overflow my sump.
Yeah I feel you. I don't plan to use one now for the same reason. I think my sump will handle the extra water.
Gonna go to Coral Gazer's tonight to get another hole drilled in the overflow box for the return, and use the other two for drains as shown.