Is there a certain window of time

[Tredge]

Higher Alkalinity means a more stable PH, lowering the TA means the PH will actually be less stable.

I have the same trouble you do with Fill water....it will always creep up when you have to replace from evaporation.....although slowly.

My plan is to get the TA down to somthing reasonable so that I can get a stable PH....then forget about the TA and Stop aerating.

Remeber that aerating will raise your PH. If you have a PH you like, then Stop aerating and dont worry too much about the Alkalinity.

Unless you have a problem with scaling I would forget about trying to "fix" the TA because your fill water will mean a constant battle....you'll never get it to stick at a low number.

No matter what you do you'll probably always have to add Acid....the good news is that your PH should stay fairly steady compared to other pools. The High TA doesnt cause the PH to shoot up....thats another problem and may be related to your TA increasing on you.

Once alk is lowered and properly aerated, it shouldn't rise sharply, right?

Thats my understanding from the technical explanations yes...but I have seen it bounce around a bit, I always attributed it to my testing or other factors.