Quote Originally Posted by Watermom View Post
You only need to shock if you let your chlorine level drop below the range that you are supposed to keep it in based on your CYA level (see Best Guess chart below in my signature), or if you have a really big swimmer load, or if you have a CC reading above 0.5. I also sometimes shock if I have a big storm that throws a lot of debris in my pool. Other than that, you don't really need to shock. I rarely shock my pool because I maintain my chemistry where it needs to be. I'm guessing other than at start-up, I probably don't shock my pool more than twice a summer and maybe not even twice. Of course pool stores tell you to shock weekly. They want your money!
+1 for me exactly. I didn't go to shock levels at all last year except on opening. I will run the pool at the highest end of the operating level or even a little higher after heavy bather loads, storms, heat waves or other weirdness. That has been adequate.