A-Maz Water Stain Remover. This water stain remover is safe to use in non-ventilated areas with no mask or gloves required. A-MAZ Water Stain Remover contains no bleaches, chlorides or gritty pumice that can cause damage to delicate surfaces, and it is also safe for Septic tanks. It is a deep cleaner that penetrates the surface material, removing all excess unwanted stain, restoring the glass, metal, or porcelain back to the original quality. It is manufactured as a paste, as opposed to a liquid or a cream and it is able to deep clean with great results, to make surfaces look brand new again. Oxidation, black streak, bluing, calcium, tarnish, salt spray and water stains simply fade away. is safe for use on house windows, windshields, shower doors, Fiberglass, chrome, porcelain, tile and grout, oxidized plating, brass, copperware, bath enclosures, sinks, toilets, fixtures, stovetops, oven, grills, pool tile and more. This product will not repair glass or reverse etching which is permanent damage to the glass.