The adjustable shutoff valve is just below the overflow, becouse the overflow box is somewhat bigger than i need, actually the pump is smaller than i need. Again, the pump is pumping 325gph becouse i have 5ft of head pressure,and if i just let the water flow to the sump without restricting the water flow it will flood over in a min. or two.I only have the valve open about a quarter of the way. By the way, i am using 1 1/4in. PVC
pipe to the sump, and 1in. hose from the pump to the tank. The pump is a CA
-3000 powerhead/pump. I am just trying to figure out why my water level wont settle in, it either rises, or falls.