Leisure Time Spa MineralsLeisure Time Spa Minerals is an easy to use cartridge containing an EPA registered mineral formula that destroys bacteria while reducing chlorine or bromine use up to 50%. This product has been proven to reduce sanitizer demand, which lowers costs and simplifies routine maintenance. It lasts up to 4 months in spas up to 600 gallons and fits most filters. This Mineral Purifier Cartridge is formulated for use with bromine, chlorine, ozone, and non