Two weeks ago, my CYA was about 25. I wanted to bring it up to over 40, so I switched to trichlor temporarily.
I've used up about 4 lbs of pucks in the past 2 weeks, but my CYA level is only 30. According to pool math, it should have went up by 22 to about 47.
Is there a reason why my CYA isn't going up as expected?