Spa Frog @Ease Floating Sanitizer for hot tubs combines bacteria-killing minerals with time-release SmartChlor™. Maintains self-regulating low chlorine level for weeks. Flips over when chlorine depletes, telling you to replace cartridge.The system will use up to 75% less chlorine which cuts down on smelly odors and increases the softer feel of the water and. The smaller chlorine levels will added longevity to your swimsuits and spa equipment. You'll also be able to decrease the number of pool shock treatments from once a week to once a month.