This is the second season I am caring for our 33K inground, vinyl pool. The pool has a west exposure and is in the sun from 10 AM till sundown. We have a lot of hot, sunny days days here in Missouri. The latest water readings this morning were FC-3, CC-0, TA-80, pH-7.6, and CYA-55. These have been typical the past 2 weeks. I plan to raise FC to 6 or even higher if I bring up the CYA level. I haven't tested FC overnight drop for awhile, but it was 0 the last time I checked. Last year, the use of dichlor and trichlor brought the CYA level well over 100 by mid summer. When I learned about the BBB method, I converted to bleach and luckily didn't have any problems the rest of the summer. When I closed the pool in September, CYA levels were still way over 100, but when I opened in early May, CYA was well below 30 (the Taylor black dot tube was almost clear; used new reagents). Where did all the CYA go? Last year I could hold FC levels by adding 3 quarts of 6% per day. This year it is taking 1.4 gal. to hold FC. Is this reasonable or should I keep raising the CYA level up to 80 as suggested for high sun pools? I would like to keep CYA as low as possible, but my current chlorine use is running about $100 per month. But then again, there's a lot of water out there. Thanks for your help.