Recently finished up a 13 month tour in Afghanistan, all was well until I got home and found out there was a different war to finght, the war on algae. MY above ground pool, 15k gallons or so, was green as the day is long. Added some acid to drop the Ph and also plenty of liquid chlorine. Pool now is a loverly milky blue color. Have added 10 gallons of chlorine last week and today still am reading close to 3 ppm. Also added a water clarifier. Pump has been running no stop for close to two weeks. I have a sand filter with Zeobryte and a hayward pump. Backwashed several times up to now and am maintaining a reading of less than ten, which is good for this unit. Before I left for Afghanistan, all I had to do with this pool is dump in 2.5 gallons of chlorine on Sunday and this baby was a clear as could be, not so much now. Ideas?? Thanks