My Chlorine level is at 5ppm using the tf100 test kit. I had 2 pucks in the inline feeder but they have been gone for 5 days now. I am using the Nature2 cartridge because it came with the pool but will switch to BBB next season. PH is 7.6 T/A is 150 and CYA is 40. The water is crystal clear but I don't know why the CH level is not dropping. The pool gets full day sun but has a solar cover on it. Any ideas?