Interesting. I cannot answer your questions, except by referring to the Taylor guide, but you make me ask related ones.....I tried to ask this before, and I cannot remember the answer. Does pH really have an effect on the longevity of your FC, or just on it's ability to sanitize? If I understand correctly, you are suggesting that because your pH is lower that a greater amount of your chlorine present is in the sanitizing, or hypochlorous acid form. Agreed. However, I dont know that you can conclude that the lower pH results in FC *lasting* longer, just that the stuff that is there can do a better job. Anyone?
And your question about keeping it at 7.2 is interesting. I would think, but I'm just surmising, that its not a big deal, as long as you dont have skin irritation from low pH. I doubt that 7.2 is acid enough to cause damage to your heater, etc, since some people have water out of the tap at 6.8 and their pipes are assumably not corroded. (?) According to the Taylor water wheel, if you maintain a pH of 7.2, and a TA of 80, with a temp of about 100-104, then you should have a Ca of 350-400. How important is that??? What does "balance" mean, anyway, aside from keeping Ca in solution, not precipitating?
