Evan asks a question implicitly I would ask FIRST before taking the steps he's indicated:
Is this a concrete/shotcrete/tile/plaster pool? Is it new or newly surfaced? If so, the curing of walls is raising your pH and your efforts will be for naught--you just need to keep adding Muriatic acid.

If, however, that's not the cause of the rising pH (such as you have a vinyl pool), a lower T/A may well help. This season, for some screwy reason, my T/A has been just around 60ppm and I haven't messed with it because my pH has been locked in at 7.6 for 6 weeks without doing ANYTHING. So...why would I raise T/A? Normally I keep T/A at 80-100 but....pH hasn't moved and T/A's "job" is to keep pH stable.

So try lowering T/A to 60 or even lower and see if the pH keeps rising.

Meantime, keep Muriatic Acid around and keep adding it. For long-term use MA is better than Dry Acid as it's just Hydrochloric Acid--nothing extra goes into the water.

Good luck!

Carl