Poollife Turbo Shock is actually Calcium Hypochlorite--Cal-Hypo. Unless your calcium hardness level is high, it's fine to use it, BUT DON'T MIX IT WITH ANYTHING ELSE! VERY DANGEROUS! (but you can safely put it in your pool when you've been using other chlorine methods. Just don't pour bleach over it, or put it in the skimmer with tabs already there).