Ok, I've been running on bleach since the end of last year when my crappy swg died. I've been reading about chemical pool volume calculation and such because I never was sure just how big my pool was. It's a 20x40 Grecian with an 8.5' deep end and around 3.5' shallow end. I've figured that at around 32-33k I think. When I added cya last year based on that volume it seemed to come up just where I thought it was going to. Anyway. While on bleach I've never been the measuring cup kind of guy. I add a gallon before it gets to the minimum FC for my cya level. Be that one day or 2-3 because it's cloudy and cold. Yesterday I decided I was gonna test before and after the bleach addition to see if the 10% I got from rural king was any good. I turned the pump on, waited half an hour, tested FC at 3; which is what I thought it would be based on being 5 the evening before. Normally I would've just added when it was 5, but it was late and I had other things going on. Anyway, I added a gallon of the 10%, waited half an hour, and tested again at 8.5fc. I took the water samples from the same spot, in the same manner from elbow deep, tested in the same location, and I use a little disposable pipette to make sure I'm as close to 10ml as possible. According to poolmath, to go up 5.5ppm FC with a gallon of 10% bleach, my pool should be closer to 18k gallons. It's bigger than that, so is this bleach just that strong? Also, last year when the swg was working and I was having to add acid every 7-10 days, the volume of acid needed to move the ph matched what poolmath said for a 33k gallon pool. Any thoughts?