Keep your hot tub in great condition and ready for use with FROG Serene Bromine Replacement Cartridges. These high-quality replacement cartridges are specifically designed for FROG Serene hot tub systems, ensuring seamless integration and optimal performance. Experience enhanced water sanitation with the complete FROG Serene Sanitizing System of Sanitizing Minerals and a low level of bromine to effectively eliminate organic matters. This innovative approach reduces bromine use by up to 50%*, making the water gentler on your skin, swimsuits and the surfaces of your hot tub. Say goodbye to harsh chemicals and enjoy a more comfortable and enjoyable soak every time. Bromine slowly dissolves in hot water so it’s easier to regulate, has far fewer odors and is less impacted by pH swings, making hot tub sanitizing more effective. Designed for convenience and longevity, each bromine cartridge lasts between 2 to 4 weeks, minimizing the need for frequent replacements. The prefilled cartridge allows for quick and easy installation and is recyclable when empty. Upgrade to the FROG Serene Sanitizing System with FROG Serene Mineral Cartridges (sold separately) and FROG Bromine Cartridge replacements today and enjoy effortless hot tub management with superior sanitation and water quality. 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 water care for your pools, hot tubs and swim spas. 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. *Compared to the minimum ANSI recommended bromine level of 2.0 ppm for a residential hot tub.