With a cya of 50, you shouldn't be letting your cl drop to 0. Actually, you should be keeping it between 3-6 all the time. As long as you aren't having any algae, etc., you only need to be testing in the evening. Then, add enough bleach to take your cl back up to 6. I would not add any more cya. We generally recommend cya between 30-50. What type of chlorine are you using?

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