Free chlorine in water with normal pH consists of hypochloric acid and hypochlorite ions.
For sufficient disinfection (bacteria reduction, etc.), free chlorine (approved disinfectant) must not fall above or below the mandatory amount. Although it is possible to greatly reduce the microorganism content in a short amount of time through impulse chlorination or super chlorination, a high content of side reaction substances result simultaneously. (see also compound chlorine, disinfection by-products, THM)
The WAPOTEC solution: