High Alkalinity

[ljckal]

When we returned home from a week vacation our inground pool was a mess. Pool is about 25,000 gallons, liner pool. Lots of rain while we were away and water level was very high. After returning home, found out that chlorine levels very low, ph levels very low and alkalinity very high (250ppm). We brough the TA down by putting in 4 gallons of Muriatic Acid over the course of 3-4 days. Then brought the ph levels up. By about day 5-6 all levels were good (TA was 110, ph 7.6). Now in just just 5 days the TA is back up at 220. Why does this keep happening and what is causing it? Ph level is good 7.6, but TA is high (220). Are we doing something wrong?