I just started at this pool thing. I am trying to clean this pool that was green with a film on it and I cleaned it and it's a little green still but my main problem is I cleaned all the grids and put the pump back together and then turned on and added the right amount of earth to the system and the pressure would stay at 12-15 for like 15 minutes then start to climb and go to like 25-30. Why is this? Anything will help because it's driving me crazy and I'm afraid to let the pump Run but need it to to get all the green out.