This winter kit helps you to maintain your pool over the winter season, so that when spring arrives, balancing your pool's water is easy. Our Jonas winter kits use specially formulated chemicals that prevent algae from growing in your pool during the winter season. Since most pool owners usually have their pool cover on, pumps and filter off, and no water cycling, pools can easily becomes a great place for algae and other contaminants to grow during winter if proper care is not taken.