I retested, and after averaging a few times, I think CYA is closer to 50. FC seemed to be holding pretty steady and wasn't crazy low when it was hazy/cloudy. I test daily, and had been at 5 or so for a while. So if I go up to slam level, I probably wont need it there long, as I'm passing CC and OCLT already. And it is ok to swim up to shock level right? The kids will kill me if on this 85 degree day I say they can't go in the pool! LOL