I was fighting high CYA last year and, through draining, got it under control. Thanks to this forum, I knew what to do. (Drain and fill and drain again.)
Now I have the opposite problem. I am getting no / barely detectable CYA reading on my test. The first time I noticed the low level, I put in two pounds of HTC brand from Wally World with the sock method. Waited a week. No change. Put in the other two pounds, waited a week, no change. About a month later, put in four pounds. Waited a week. No change. Went to the pool supply store (I know, blasphemy) and tried their brand. No change.
I thought maybe my reagent was too old, so I got some fresh. Still no reading. All other chemicals are balanced, but I'm burning through chlorine. Any advice anyone can give to me would be greatly appreciated.