I'm wondering what kind of problems could be caused by high Total Alkalinity (240). In the situation I am thinking of, the pH was around 7.5, but the TA was up around 240. My boss decided we had to add ph- to the pool to lower the TA. When I asked him why, considering the pH was fine, the season is over and the pool would be closed in about a week, he said that high TA would stain the liner. I've heard that low pH would stain a liner, but never high TA.
If I understand correctly, high TA combined with elevated pH will result in scale. But since scale is more soluble in colder water, I don't see that being a real concern going into winter.
So I guess the question in all of this is, What problems can be caused by high TA?