Hi! I help take care of the pool in our condo community. Last year, the health department said our cyanuric acid was too high. They never shut us down, but it was always higher than their allowable level. I believe their limit was 75, and we were around 100. I drained about half the water out and refilled. That got it down to about 80. Just couldn't get it any lower. The health department said that the reason was because the paint in the pool (it is an inground) walls and bottom had absorbed the acid and we would never be able to get it low unless we repainted. In searching the internet, I have not been able to find this mentioned. If it's true, it's probably out there and I just haven't seen it. Just wondered if anyone else has had this issue. Bottom line, draining half the water out helps, but it doesn't get us where we need to be. Thanks.