I feel your pain Barry. The reason I ever found this site was my HIGH cya and the problems it gave me. THe way I dealt with it was draining it until I got the cya down to 90 and bought Bens test kit so I could test the high cl needed.

I kicked myself more then once for listening to the clerk who sold me the stablized chlorine and the pucks to go along with it. But anyway...

I know its not really the solution you were hoping for , but my advice is drain some more to get it down and get a test kit that allows you to test cl at the needed range

If there is a silver lining , once you do get it under control , CL levels are pretty easy to maintain .. dont lose much to hot sun