First time opening - in ground vinyl lined - 28,000 gal - cartridge filter, HAyward pump. Everything went back together fine, but when I started up the pump to circulate, the hose that is hooked up between the pump and the filter (used for draining water) was draining water. When I tried to close the valve so that the hose line was closed, I couldn't locate the right position. It seemed that something changed since the previous year, as I cannot close that side of the valve. Does anyone know why this could be the case?