Take a look at the Best Guess Chlorine Chart in Janet's signature above. With a CYA reading of 64, your shock level is going to be 20ppm. So, you need to add enough chlorine to get the cl up to 20 right now and as Janet advised, try and hold it there. Your chlorine levels are too low and I'm sure she is right -- you have an algae bloom trying to take over your pool. Don't let it!

You want to hold it at shock level until you can go from sundown one evening to within 2 hours of sunrise the next day without losing more than 1ppm of chlorine and without having a CC reading that is any higher than 0.5ppm and having clear water. At that point, we usually suggest holding the chlorine high for one extra day for added insurance and then you can let the chlorine level drift down and keep it within the minimum and maximum levels based on your CYA reading.

Since your CYA is 64, I would suggest not using the trichlor pucks any more. They are stabilized which means they add CYA and yours is high enough.

Also, your pH is a little low. Bump it up some with some 20 Mule Team Borax (laundry aisle at Walmart).

Hope this helps. Welcome to the Pool Forum!

Oh, almost forgot. Will you please put your pool's information in our Pool Chart. It makes it easier for us to help you.
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