Jason, I copied the following from another thread and I could use more info:
"PH can go up for a number of reasons. The most common is CO2 outgassing caused by aeration of the pool (rain, kids playing, SWG, waterfall, spa, etc). Blown in dust can sometimes be fairly basic, raising the PH. New plaster will raise the PH for several months to a year.
If you compensate for PH increases from CO2 outgassing by adding acid reguarly, the TA will go down over time."
The only thing on the list that seems to apply to us is the new plaster in March. We have been adding about 2-4 cups muratic acid about every 4 days or so. (Since I am afraid of the MA, I just guestimate it and do not measure.) But the question I have for you is: If our ph is doing this climbing thing at the end of the season, what do we do for the winter? Is it still an issue when our water temp is below 60? Thanks in advance for your help. btw, your calculator is great!