Thank you, I was hoping to get an answer like that and convert to bleach. Initial pool inspection guy set me up with the tricolor pucks, and I've had 4 in a floater consistently, and have shocked with 2 bags of shock 4 times in a month. I think that my hard water is preventing good chlorine saturation. Will the bleach work better? Also, I estimated the cya, as it was just above 100.