In The Swim Pool Shock – 68% Cal-Hypo Granular Sanitizer for Crystal Clear Water – Defends Against Bacteria, Algae, and Microorganisms - 12 X 1 Pound;

IN THE SWIM's Pool Shock Swimming pool shock treatments are an essential aspect of spring pool opening but can also be used to give your pool a quick chlorine boost. Pool shock is our most popular and versatile pool shock treatment, used to kill algae and bacteria and remove micro-contaminants that make pool water cloudy. Use our Pool Shock to kill visible algae blooms and invisible bacteria, which could cause illness to swimmers. Your daily chlorination of the pool will kill most pathogenic bacteria, viruses and microbes, however to be sure that the water is sanitary, it is good practice to 'shock the pool', or super-chlorinate the pool every few weeks, to oxidize everything in the water, especially the invisible germs that may be harboring in the water.