Star Brite® Aqua Water Treatment and Freshener. Maintains perfect drinking water quality in boats and RVs. - Prevents foul tasting or smelling potable water. - Can be used as often as needed to ensure quality of bathing and drinking water and ice. - Prevents water from taking on chlorine, sulphur, plastic or metal odor or taste. - 1 fluid ounce treats 20 gallons of water.