Check the listing for details. Poolife NST Prime Chlorine Tablets 20.2 lb. Condition: New. Listed at 116.99 USD. Poolife NST Prime Tablets are the perfect solution for keeping your pool clean and safe from harmful bacteria and organic contaminants. The unique octagon shape and proprietary slow-dissolving Cal Hypo technology ensures extended release of the sanitizer for days, making maintenance of your pool a breeze. Unlike other chlorine tablets, Poolife NST Prime Tablets do not over-stabilize your pool by adding Cyanuric Acid (CYA) to the water. This makes it compatible with all pool skimmers and other sanitation systems like chlorine, salt chlorine generators, ozone and mineral systems. With Poolife NST Prime Tablets, you can enjoy crystal clear water without any hassle. Usage Tips: For use in all pool skimmers Skimmer basket must be free of all other water treatment products before adding tablet(s) Can also be used in the Poolife NST Prime Feeder Replace with new tablets as needed For optimum product performance, swimmer comfort and crystal clear water, always maintain pH from 7.2 - 7.6, total alkalinity from 60 - 120 ppm, calcium hardness above 200 ppm and free available chlorine residual between 1 - 4 ppm Compatible with chlorine, salt chlorine generators, ozone and mineral systems Active ingredient: Calcium Hypochlorite (Cal Hypo)