Do you have a vinyl pool? If so, when the pH is correct (7.3 approx) if the T/A is 180 or less it's OK, 200 or more, you'll need to lower it, between 180 and 200 is your choice.

If you have a concrete/plaster pool, you'll need to lower it to 120. (again, AFTER you've measured it with a corrected pH).