How long after I add the acid should I wait before retesting the pH? I've got about 20,000 gallons in the pool right now and it holds a totally of approximately 28,000 gallons. It's not up to the return nozzle or the skimmer yet so while I have the pump running, the return is just spraying into the pool. I think that should give me some good aeration. I've stopped filling it for now so that I can spend a little time trying to get the alkalinity down. Last night I tested the pH and it was 8.2 which is the highest number on my kit. I guess it could have been higher and off the kit's limits. I added a whole gallon of acid and let the pump run and return spray into the pool all night. I just tested the pH again and it was at 7.8. This time I added a half a gallon of acid. The pump is still running. I want to test it again as soon as I should to keep on top of it. How long after adding the acid should I test the pH again? Thanks.