For use only in certain hot tub models up to 600 gallons Artesian Elite, Artesian Island optional on Artesian Island Elite and South Seas; Marquis Crown optional on Marquis Elite, Vector and Celebrity; Caldera Vacanza; and Hot Spring Hot Spot FROG Sanitizing Minerals work with SmartChlor sold separately a patented, timereleased chlorine that automatically delivers sanitizing power to meet demand. Together they create crystal clear Fresh Mineral water and give peace of mind FROG ease Cartridges are prefilled for no mess, no guess and no stress. FROG sanitizing minerals eliminates organic contaminants, condition the water for softness and absorb acid to help keep pH balanced. You use up to 75 less chlorine* with FROG ease, making water easier on skin, hair, swimsuits, and your hot tubs surfaces. With FROG ease, you shock only once a month, or when draining and refilling your hot tub thats so much easier than shocking after every use it saves time and the frustration of constant shock treatments