Keep your hot tub in ready to use condition with the FROG @ease Replacement SmartChlor Chlorine Cartridges, for use with the FROG @ease Floating Sanitizing System. The hot tub replacement Cartridges are cyanuric acid free, so there’s no buildup & no more irritating, smelly water; ideal for hot tubs up to 600 gallons. FROG @ease uses SmartChlor, a patented chlorine formula that consistently releases a low level of chlorine to avoid the yo-yo of chlorine levels when you shock the hot tub and then get in the water. This cartridge formula combined with FROG @ease Mineral Technology creates Fresh Mineral Water for continuous crystal clear water and peace of mind when it comes to hot tub maintenance. With FROG @ease, you use less chlorine, making water easier on your skin, hair, swimsuits, and your hot tub’s surfaces. Each Cartridge lasts 3 to 4 weeks. For more than 25 years, FROG has sanitized pools, hot tubs and swim spas with its innovative, patented Mineral Technology that makes water care easier. FROG's prefilled cartridges mean no mess, no guess, and no stress pool, hot tub and swim spa water care. Each FROG product helps make your water Cleaner, Clearer, Softer and Easier. No matter what size pool, hot tub or swim spa you have, FROG has a solution for it.