The eco friendly and chemical free magnoloo from ecozone is the anti limescale toilet descaler of choice guaranteed for five years simply drop one magnoloo descaler or two in very hard water areas into the cistern to keep your toilet free from a build up of deposits for up to 5 years the chemical free magnoloo can help to prevent or eliminate the unsightly stains of limescale built up in the toilet how well when water is treated magnetically the calcium carbonate doesnt form a hard limes