What should the pressure be on the gauge that is on top of the Pentair Clean and clear filter housing for a pool of my size? The pool sweep no longer moves even though I have broken it down and all of the parts are working and water is flowing through all parts and jets. There just doesn't seem to be enough pressure to make it operate. So do I need to check my whisperflow or the back up pump for the polaris? And if the backup pump how would I test it?