Pool very green. I have studied Pool School and I think I understand all the concepts. I ordered and received the TF test kit.
My CYA was nearly zero so I added enough to get it to 40. I left town for a few days while the CYA dissolved. This morning I tested
and CYA was 40-45 which calls for about 16ppm shock level. I added 4 jugs of bleach (8.25% at 121oz per jug) according to the Pool Calculator. I waited half an hour and tested FC but still 16.5. I waited another half hour and still 16.5. Why isn't it dropping?