First, maybe this is better addressed in The Deep End, for it is surely over my head.
I've got a question here (very bad grades in chemistry, so bear with me please).
I read that at lower TA, pH is less stable. Does that mean that if something occurs to disturb the pH, higher OR lower, it will move rapidly? Just wondering because in aquariums, there are processes going on that acidify the water and with more RO water in a fish tank you were more likely to have pH to crash. Now my question is, are there similar processes going on in a pool? In the fish tank that was the processing of waste by bacteria. Now in the pool, you hope to have all waste processing going on via chlorine, with no bacteria in the pool. But what is going on in a pool? Are there processes going on that would push the pH either lower OR higher?
I'm just wondering, with low TA, would you be just as likely to one day find it super low as you are another day to find it super high? Is it possible to be managing with a low TA, and a normal pH of whatever, then one day it is 8.2 for no apparent reason? I mean, the first thing one might do would be to grab some muriatic acid to deal with the pH but if that happened due to low and destabilizing TA, that might be the wrong answer. If the pH was super low, the first response would be correct, but could it go the other way?