How high you need to shock a pool depends on the CYA (stabilizer or cyanuric acid) level. If you don't shock high enough, it won't kill the algae. If you shock too high, you risk fading your liner. (Take a look at the Best Guess Chlorine Chart in my signature below for more about the connection between chlorine and CYA.)

Some brands of chlorine are putting copper in their products. You do NOT want copper in a pool as it is the copper that stains things (including light-colored hair) green! Look at the label to see what all of the ingredients are.

Why are you shocking your pool? Do you have algae? Do you have a drops-based test kit? Can you provide a complete set of current water testing results taken with a drops-based kit? Make sure CYA is reported.

Also, give more details about your pool and tell us what size pump and type of filter you have. Then, someone here can better advise you.

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