water level was fine until I tried to open pool this week. It is a large spa/small pool Hayward DE filter. I cleaned the cell, vacummed, added DE, turned the pump back on and the water level started going down, pretty fast. turned it off and the leveller got it back up. did this 5 times!! it even now drains when main drain and skimmer valves off and vacummer on. Help! I'm not sure what to do. pressure is inbetween the green and red lines. water not seeping anywhere.