Quote Originally Posted by han78216 View Post
This doesn't make sense to me. I moved to a house where previous owner exclusively used tablets for many years. Sure, CYA ended up being somewhere between 240-300 but shouldn't it have gone up to much higher number?
Not necessarily. If he had a sand filter, backwashing and other water loss would limit the upper concentration. But . . . . test results showing 240 ppm CYA are highly suspect. Unless he was VERY careful and did VERY good dilutions, his 240 ppm might have been 600 ppm!