C.H. Cleans Hoses for Tanks MSD - 1 QuartC.H. dissolves scale and calcium build-up and adds life to your boats sanitation system while providing less maintenance and less cost over time. C.H. is specifically designed to remove uric scale and calcium carbonate from black water systems - from the toilet to the holding tank - without having to remove hoses. Simply pour the recommended mixture in, allow to sit in hoses or tanks and let it go to work! By properly maintaining all connections and hose