Use the Protech Chlorine Shock to ZAP organic pollutants bacteria, and algae. This quick dissolving shock does not require pre-mixing, and will not cloud the water. The PROtech Chlorine Shock is most effective when used on a weekly basis to eliminate bacteria, organic buildup and control algae. This shock is a pH balanced formula so it will not affect pH Levels, thus cutting down on costs of other balancing chemicals!