I hav been running my new 4'x20' solar panel for a week or so with some success (when the sun isn't behind a rain cloud). I have a diverter on the system, which includes a Hayward DE filter and 50 gpm pump. The filter was running at 11 psi before I added the panels and I had it anywhere from 14 psi to 17 psi with the diverter through the solar collector. I'm fixin' to add my old beehive GAME heater in parallel and I need to know if I need this socket check valve I bought at Lowes. Everything is on the ground right now and will be for the foreseeable future.