I have a 25,000 gal in ground plaster pool, CYA = 45-50, CA = 270. Totl AL = 70 pH = 7.5. I went through a shock and it finally stabilized at 22.5 ppm overnight. Then, the next day the FC plummeted to 12 during the day. Today it fell to 3 even after adding 2 quarts of bleach (8.25%).
This seems to be a large amount of chlorine usage. What is the normal chlorine usage for a pool this size in the summer????