Aeration occurs continuously, if you just use the pool and don't cover it. You can increase aeration rates, through a variety of means. For example, a pool party of middle school boys provides very effective aeration!

But it's not necessary in your case.

6.8 - 7.0 is fine for people and liners. The problem is that, with phenol red testing, 6.8 is about the lowest (most yellow) color. If the pH is 6.8, the solution will be yellow, but if it's 4.0, it will STILL be yellow, with only a small visual difference. What we tell people is that, when they test their pool, 6.8 *really* means 6.8 or LESS, and 8.2 *really* means 8.2 or MORE.

But, in your case, if you use small acid doses to lower the pH, you won't overshoot much, and the high alkalinity (and accompanying off-gassing of carbon dioxide) will naturally cause the pH to rise.

High TA can reduce the efficacy of some algaecides -- but you shouldn't be using any, so that's not really an issue. And, high TA can make it impossible to use cal hypo to sanitize, without clouding the pool . . . so don't use cal hypo.