Electrolytically generated Ag+ and Cu+ ions are potently microbiocidal although somewhat slower acting than chlorine they are much less subject to degradation, having residual antimicrobial potency lasting for months. The recommended minimum level of free chlorine for disinfection of public swimming pools is 1 mg/liter (1 ppm). This level is difficult to maintain due to the chlorine-demanding organic material introduced by bathers themselves as well as the environment. Consequently the residual level of chlorine will have often dropped to 0.1 to 0.3 mg/liter after 24 hours.

Eye and skin irritation may also occur at the minimum chlorine level needed for effective disinfection.  Under Staphylococcus challenge, the combination of Ag+ and Cu+ together with free chlorine had a faster log 10 reduction of microbial numbers than did treatment with a high level of chlorine alone. This combination allows for a much reduced or zero level of chlorine.