I have, for reasons beyond the scope of this particular question, used trichlor tabs in the autochlorinator for the past 8 weeks - nearly the entire season. My values have remained steady: FC=3, CC=0, pH=7.5, CYA~30-40. The pool is in full sun, there's a daily swimmer load of 3 dogs and 1 human for ~ 1.5 hours. We've had a lot of rain and I do have to top the water off a couple times a week; these factors may have contributed to the CYA level not rising in any appreciable way.

I've never had a CC reading and have not applied a shock treatment other than at startup and closing each season.

Anna