I have an above ground, round 13,000 gallon pool.
My CYA is around 40. My pH is around 7.5 I (try to) keep my chlorine around 10. The temperature is around 75 degrees, and my pool gets full sun all day.
This is my question: During the day, my chlorine levels consistently drop between 8 to 10 points. So, in other words, if I start my morning with a chlorine level at 12, by the end of the day, I'm down to 2! IS THIS NORMAL???
I put in a jumbo gallon jug of 6% chlorine just about every night, but I can't get the chlorine to stay in the pool. I've done the overnight test and the levels stay stable overnight.
Regardless, I shocked the Sh** out of the pool this weekend, just to be sure, but I'm still having the same problems maintaining my levels.
So do I raise the CYA even higher? Is there something else possibly zapping my chlorine? Is my pool possessed by cholrine-eating gremlins?
Any advice would be much appreciated!