Some people do add it as a preventative. Others don't. I never use it except at closing and then I put in a double dose. If you are diligent at testing your water and keeping your chlorine at the appropriate levels, then you don't really ever need polyquat. In my opinion, why spend the money on something you don't really need. Of course, that is only my opinion. Some people do use it and that is fine, too.

Watermom