Pool water composition always includes some undesirable elements that actually contaminate the water and reduce the efficiency of the disinfectant or sanitizer. Material such as hair spray, suntan oil, cosmetics, perspiration and other organic material react to combine with the chlorine in the water to form “combined chlorine”.
Once “combined chlorine” forms, it acts as a very poor disinfectant, contributing to eye and skin irritations and the forming of unpleasant chlorine odor. Pools with this problem are often inaccurately accused of having too much chlorine.
Routine shock treatment is necessary to destroy combined chlorine compounds and restore the chlorine sanitizer to “free chlorine” efficiency. A pool can be shock treated by adding large doses of chlorine, commonly referred to as superchlorination, or by adding a non-chlorine shock such as GLB OXY-BRITE or Applied Biochemists SHOCKTRINE.