HTH 52017 Shock Treatment, Solid, Chlorine-Like, 13.3 oz Pouch (Pack of 18)

HTH® Shock! Treatment is the original swimming pool shock designed to boost chlorine levels and kill bacteria and algae for a clean, clear pool. 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.