HTH 3 In. 3 Lb. Ultimate Chlorine Tablet

6-in-1, 3 In. tablets sanitize, protect from the sun, clarify, prevent stains and scale, controls algae, and has a built-in water softener. Trichloro-s-Triazinetrione 91.1%, Zinc sulfate monohydrate 3.5%, other ingredients 5.4%. Available chlorine 83%.