The topic "CYA Discussion" seemed to be open ended. I have converted to the BBB manual method and used 3-3qt jugs of 6% bleach per day when my CYA was at ~90 following a 50% refill (Yes I was in bad shape. Couldn't get PH up or the TA down, and didn't know my chlorine at 3 ppm was useless.) These 3 jugs represents about a 50% loss in FC per day to maintain the min FC per the calculator. I did a 20% drain and refill and am reading something between 65 and 80 before my eyes cross trying to see the dot. Closer to 70 I think which corresponds with the dilution ratio. That results in a lower min FC level and I'm thinking that my bleach usage will go down accordingly. However, before I continue the feed and bleed to get CYA on down to the 40 or so level, what is the recommended CYA level for a 18x36 vinyl pool which is subjected to full sun all day? Also, I think I read in another post somewhere that a 50% loss of FC per day is expected for a sunny pool. Is that right?
Your suggestions have been and continue to be GREATLY appreciated.