Ok, gurus....please help. We are total newbs. We closed up pool and left sand filter on closed all winter instead of winterize. Our psi is 25, even when off. when on, it jumps to 36. We've backwashed and it does nothing to the pressure. The water coming into the pool is so strong it's almost bubbling, even when angled down. I don't think it's a broken guage. I tried recirculate and it's the same psi as when it's on filter. How do we get the pressure down? We have a waterway sand filter (18", I think) with a 1 hp pump, single speed pump. Things worked great last season, our first. I predict it has something to do with closing the valve all winter. Please help because our pool is getting algae. Thanks!