Unlike other products that contain toxic and corrosive acids Mineral Magic is based upon an organic salt that effectively removes hard water and rust stains without the harmful side effects that other products have. Mineral Magic has been shown to outperform acids such as phosphoric, citric, lactic, oxalic and sulfamic in removing calcium salts. Use Mineral Magic to clean: Tubs, shower stalls, toilet bowls, sinks, glass, chrome, fiberglass, stainless steel, tile, masonry, Porcelain, coffee makers and more!