Facts:
Indoor Home Pool
Age 4 years
Plaster finish
Size 12x16 – approx. 7000 gallons
Sanitation via UV and a 3” chlorine tab each week
Stabilizer – Arm and Hammer pool maintenance tabs – 1 each week
Pool is covered 99% of the time
Light use (obviously)
Pool is heated to 89 degrees FH
Pool is located at 8800ft above sea level in high country of CO

My Question:

I beat my head against the wall with creeping TA – my fill water is high in TA, but when I add water, I add MA to lower, then use sump-pump on step to bubble aerate and return PH to appropriate level. What I don’t understand is if I don’t add water, why does my TA Creep up?