I can't get the chlorine to stay in my pool. 20 x 40 IG. PH = 7.3, ALK = 100, CYA = 35, Hardness = 210. I have 3" pucks in the chlorine feeder and the FC goes to 0 within 12 hours. I had a CYA of 0 last week. I added 8 lb of stabilizer and got the CYA up to 35. I thought that would solve my problem but I still can't get the chlorine to hold. I have been adding 1-2 gal of bleach daily which gets the FC up to 4. Then 12 hours later it's near zero, even with the pucks in the feeder. The pucks have always worked well for me throughout the summer. I just add bleach after a heavy usage to boost chlorine. The pucks cost more but are much easier. The water is crystal clear. I can't figure out this problem.