HTH® Super Shock pool shock treatment is the 4-in-1 powerful pool shock designed to boost chlorine levels and kill and prevent bacteria and algae for a clear, healthy pool. Each lb of Super Shock packs a powerful punch, treating 13,500 gal and restoring crystal clarity in just 24 hr. This pool shock is great for all pool types and won't fade your pool liner. Test and apply shock treatment directly to your swimming pool every week to keep free available chlorine levels between 1 and 4 ppm for healthy swimming conditions.