HTH Pool Care 1 Lb. Shock Advanced Granule (6-Pack) (Minimum 6)

Powerful 4-in-1 formula. Contains Cal Hypo that kills and prevents bacteria and algae as well as reduces chlorine odor and irritation for crystal clear, healthy water. Traditional chlorine products contain cyanuric acid (CYA). When too much CYA builds up, it can cause overstabilization or chlorine lock, and cloud your water. The fast-acting, fast-dissolving Cal Hypo formula provides chlorination without adding extra CYA for a beautiful sparkle all season. This product is great for all pool types and will not fade your pool liner.