Hillmark Scalex Heavy Duty Home Descaler Super Concentrated Home Descaler Lime scale and calcium build-up decreases the efficiency of hot-water appliances. This can increase running costs and shorten the life of the appliance. This is particularly severe in hardwater areas. The super concentrated formulation of Hillmark Scalex: Rapidly cleans scale from plastic and metal parts (including internal pipes and valves). Removes rust stains and hardwater deposits. Great for general rust and lime removal from bath tubs, toilet bowls and sinks.  Easily removes tarnish and mineral deposits from stainless steel shower heads, vases and glassware.