I just got my pool replastered and a fresh fill added. The start-up guide I got from my plasterer calls for the TA to be at 80 and the pH between 7.2-7.6. I use dry acid (sodium bicarbonate) - a BioGuard product called "Lo 'N Slo". What I've found is that, while it brought down the pH to 7.4 from the original 8.8 of the fresh fill, the TA has only dropped from 170 to 150. I can't imagine how I would have gotten the TA down to 80 on the first day after filling. Actually, I can't imagine even getting the TA that low unless I would also bring the pH way down - probably into the acid range. I guess I could take the pH a bit lower, but I'll bet that will only drop TA down to 120-130. Any suggestions? If there is no problem with the new plaster with the TA at 150 where it is now, I won't even worry about it. My TA has hardly even been that below 100 except for one time when it was 66. The pool store told me to bring it up.
Thanks for any thoughts. I don't want the new plaster to scale, but neither do I have any idea how to bring down this current TA reading without also dropping the pH lower.