Are there any other possible reasons for CYA loss besides draining/splash out? My CYA has dropped over the last month despite adding CYA in efforts to bring it up 20 ppm. The pool is getting heavy use and it has been very hot and sunny here in Houston. Salt has not dropped a proportional amount so I don't think its all attributable to splashout. I am using TFTestKit for testing and all other numbers are in good range.... I am adding acid daily for .2-.3 daily pH rise.