Clear and Safe Chlorine tablets are used for the sanitisation of your pool, spa or hot tub, it's an essential chemical to keep the water, you and your family CLEAR & SAFE\u2122 from harmful bacteria and germs that naturally occur in untreated water. This product provides a stabilised sanitisation that kills bacteria and viruses.\n\nWater in pools and spas should be tested daily, you are aiming to achieve a pH level reading between 7.2 and 7.6 before adding the chlorine. Use pH+ or pH- to adjust if necessary. Pool free chlorine levels must be between 1ppm* and 3ppm* and spas should be between 3ppm* and 5ppm*. Maintain these levels to keep your water CLEAR & SAFE\u2122.\n\nThese are high strength slow dissolving tablets, they take 2-3 days to dissolve in a hot tub and 3-5 days in a colder swimming pool. If they dissolved too quickly the chlorine level would become too high and hard to control. The dissolution rate also depends on how they are being dosed, high water flow around5