Maintain healthy, clear water all winter long and make next year's opening easier than ever! The patented pre-measured delivery system and all-natural concentrated formula is safe to use with all pool surfaces and filters. The Winter Pill will not affect water chemistry and can be used with existing closing kits or as a stand-alone product. It keeps the chemical demand low, allowing your other winter chemicals to last. The specialty chemicals are contained in pre-filled, ready-to-use plastic capsules simply pop out the pre-marked hole then place directly in to the skimmer basket. Once the WinterPill is empty, simply remove from your skimmer. No measuring required. As water circulates, the chemical slowly disperses into the water to treat the pool. Designed to maintain the appearance and quality of pool water. It also is great at preventing stains. Should be used in conjunction with a Leisure Living Winter Kit I Ball treats 30,000 gallons.