InSPAration 7479 Tranquility Crystals for Spa and Hot Tubs, 19-Ounce Uses blend of aromatherapy crystal specifically formulated for Spas, Hot Tubs and Jetted Baths Enhanced with Vitamins, Minerals and Natural Extracts Leaves skin soft and tired muscles rejuvenated Masks chemical odors and will not stain or harm woods, fiberglass, acrylics, or plaster Has no oils and will not clog filters or affect water chemistry