Overflow problems

[reefwars]

Can you post some pics?

Fwiw a ball valve is useless , especially if your sump is in the basement , you need a gate valve.

In order for it to work flawlessly you also need a return chamber that keeps a steady water level , the higher the water level the more downward force the water hs from weight there for a little more power and you then have to slightly open your gate valve more .