Designed to control and monitor chlorine levels. Use to disinfect water in hot tubs, spas and swimming pools. Tablets dissolve slowly over a period of time for a steady flow of chlorine in to the water and specifically formulated for the disinfection of Spa, Hot Tub Water and Swimming pools. These tablets are best used in a floating dispenser. DESIGNED TO MAINTAIN WATER CLEANLINESS & SAFETY - Control and monitor chlorine levels. Use to disinfect water in hot tubs, spas and swimming pools. EASY TO USE - Tablets dissolve slowly over a period of time for a steady flow of chlorine in to the water and specifically formulated for the disinfection of Spa, Hot Tub Water and Swimming pools. SUITABLE FOR FLOATING DISPENSERS - These tablets are best used in a floating dispenser.