So when the return pump is off. It backflows down the return line into the sump. Ok I think I get it know and finally understand. Thanks ccapt for answering all my questions. Heres one more. The only return line flow director I could find was on DR Fosters&Smith. Do you know of somewhere that makes a flow director that connects directly to 1/2" PVC
to eliminate having to adapt the pvc
to tubing that fits over the flow director. Maybe if someone could link me to some pics of how their return line is connected to their flow director??