It is recommended to clean the Moccamaster after 100x brewing (1 pack of filters) to keep the perfect cup of coffee. Instructions for use: durgol universal frees all household items of limescale, quickly and effortlessly. Its formula guarantees efficient, food-safe and environmentally compatible decalcification and is gentle on materials.Pour 1-2 cups (150 ml) of durgol universal into the water tank and dilute with the same amount of tap water. Run the solution through the machine, then rinse twice with tap water.