The pH is what matters. TA being high only is a problem if it makes the CSI super-positive. Otherwise, higher TA will make the pH rise faster naturally. Add acid when your pH gets to 8.0 to bring it down to 7.6 (you need to know the TA when adding acid for PoolMath to give the correct recommended dose), and then the TA drops a little. pH naturally rises, acid added, pH and TA drops, and you repeat. Over time, the TA will lower and the pH rise will slow down a bit until you get down to TA in the 50-70 range and acid addition becomes rare.