Works Great On: Soap scum; calcium, lime, & rust; grout & grime; hard water stains. 45% more than 22 oz. Mean Green Bath, Tub & Tile Cleaner has been formulated for your tough problems like soap scum and hard water buildup without harsh fumes and sticky residue. Removes: Soap scum; lime stains; calcium (hard water buildup); rust stains; discoloration; soils. Great on: Ceramic; brass; showers; tile; porcelain; copper; bathtubs; hot tubs; grout; stainless steel; sinks; pools; fiberglass; concrete; toilet bowls; boats.