From a water balance standpoint and from a practical standpoint, a high alkalinity will continuously raise the pH. You will always be adding acid to a pool that has high alkalinity.

Does alkalinity affect pH?

In simpler terms, total alkalinity is a measurement of the water's ability to resist change in pH. In particular, alkalinity slows the reduction of pH. Too much alkalinity is actually a source of rising pH. The more alkalinity you have, the more acid it takes to reduce pH.

Should I raise pH or alkalinity first?

You should test alkalinity first because it will buffer pH. Your reading should be in the range of 80 to 120 parts per million (ppm). If you need to increase the alkalinity, add an increaser. To lower it, you'll add a sodium bisulfate.