Cal-hypo is far more likely to raise pH than bleach. Use that instead. The pH of bleach is high, but it's generally 1 gallon's worth against 10,000 or 20,000 gallons, so it's usually not effecting a change.

Aerating doesn't lower T/A--that's been a confusion around the board. But it DOES raise pH under certain conditions that are part of the T/A lowering process and may be contributing to the rising pH.

I would raise T/A and see if it helps.