For the fourth summer in a row, the entire time we've had our pool, I'm having trouble getting the CYA up. I added four lbs of Cya last week and, while the ph dropped exactly as expected, the. Cya didnt move a speck. I'm going to add another 4 lbs. Every year I go through this, adding more cya and it inching up very slowly. By the end if the summer I maybe get cya to 50 and then it's time to close. In the spring cya is almost all gone.
Any idea of cause? I know I could be underestimating my water, but not to the point of NO cya rise. Pool is 18 by 36, kidney shape with a bump on the side, shallow end is 3 ft, deep is 8 ft I doubt it is converting to ammonia because my FC looks good.