The Poolhacker Pool Winterizing Kit is designed to keep your pool water clean and clear all winter long. With Poolhacker's exclusive formula of effective scale and fouling inhibitors, opening your pool next year is easier than ever without compromising water chemistry, and this kit can be used in conjunction with existing closing kits or as a stand-alone product. Safe for any pool surfaces, each kit maintains up to 30,000 gallons of pool water. Make sure to use a pool cover as well.