The best guess table is to help you determine how much chlorine you need to maintain in your pool all the time, and how high to shock the pool when that is needed. It is based on the cya level in your water. For example, if your cya level is 40ppm, then you must keep your chlorine between 3-6 all the time and if you need to shock, you will need to take the chlorine level up to 15.

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