Bio-Dex Tile Cleaner removes Calcium Deposits, Dissolves Oil, Grease and Most Soils in Minutes! Use Directly on Heavy Calcium Deposits. Removes Calcium - Fast! Because this product is the strongest calcium remover available it must be used with care. Wear rubber gloves and eye protection. Do not drip on decking or plaster. Always rinse after application. Lower water line below calicum line. Do not lower water to allow #300 to drip onto the plaster. DO NOT USE ON MARBLE, GRANITE OR ANY TILE THAT IS NEW OR CLEAN. APPLY TO CALCIUM DEPOSTS NOT TO CLEAN TILE AREAS. Use Quick 'n Thick Tile cleaner for Maintence Cleaning. Do not use #300 Tile as a maintence cleaner or it is possible that the glaze will become dull. Bio-Dex QUICK 'N THICK is best for maintenance cleaning and Bio-Dex PROTECT-ALL SUPREME is best for preventing calcium build-up in the first place. Use at your own risk. We are not responsible for damages - bodily or property. Read the instructions carefully and always do a test first. - For Questions please call Bio-Dex (800)617-3477