Got my 8 gal Liquidator today. I tried to blow air with my mouth through the check valves in the flow direction. There is a noticeable resistance. Is this a defect or a design flow, or is it common to LQ's check valves?
One would think that a check valve shouldn't have any resistance in the flow direction. My pump and all the setup is above water level. Should I or shouldn't I use these valves?