My cya was 20 and I was using more bleach per day than I wanted. I added 4 lbs of stabilizer to bring my cya up to 40 and my usuage dropped in about half. My demand went back up about 3 weeks later, rechecked my cya and it was down to 10. I had to backwash 2 times in the last 2 weeks and had about 3 inches of rain. Yesterday i added another 4 lbs of stabilizer and am using 7PPM of bleach per day. What am I doing wrong?