You can bump up the CYA, but remember it takes several days to give you a reading. Then you'll need to follow the "Best Guess Table" for the maintaining the pool.

Lowering T/A from 110 to 70 shouldn't take long. Remember: When the pH goes down to 7 after you add acid, the T/A will go down with it. Aeration brings the pH back up without raising T/A. So....the first time you lower T/A you'll be able to figure out how long it takes.

Hope that helps.

Carl