I have a 24' AG pool with a Hayward ASL Series C1250 cartridge filter. I had a very bad algae bloom when I first opened it, but have gotten that under control. Everything is in balance and I have been maintaining a shock level for a week now and running the pump 24/7, but the water won't clear up. I replaced the cartridge with a Pleatco three days ago and it has gotten slightly better as I can just make out the bottom of the pool now. It seemed odd that it hadn't cleared by now so i dropped a couple tablespoons of cyanuric acid into the skimmer. Low and behold I saw crystals of the acid coming out of the return. It seemed to me that the filter should have stopped them. Can anyone offer any insight?