So today I started to set up the tank. I took my sump outside and connected the water pump to it. There is a 1" PVC inlet pipe from the sump to the pump, and the outlet on the pump is also a 1" Pipe reduced to the half inch rubber hose. The sump had a downward slope with gravity feeding water to the pump. My pump only works when the gate valve is halfway turned. If I open the valve all the way it loses the vacum or suction. The pump is a gen x 3, rated around 900 gph. ideas? I was simply holding the outlet hose while it sputtered water out of the sump. Once it is opened more than halfway it loses suction.