Quote Originally Posted by 94ukgrad View Post
Is this low level of clorine actually killing the bacteria and whatever else is in my pool? The pool man told me I needed to bring clorine to shock levels at least once a week to actually kill the bacteria in my pool.
Mark,

Most bacteria are killed very quickly at normal chlorine levels -- even at very low chlorine levels. The main reason for keeping the chlorine levels as high as are recommended on this forum is to prevent algae growth and to oxidize bather waste reasonably quickly. Your pool man is wrong about needing to shock to kill bacteria. I just wrote some technical details about this at TFP in this post and in another forum I wrote about how chlorine is not like an antibiotic where resistance from mutation was possible in this post.

Richard