Scalemaster^® Magnetic Limescale Inhibitors prevent limescale build-up by influencing the type (crystal structure) of the limescale precipitated. Laboratory research has shown that the growth of limescale crystals is affected by the application of the magnetic field causing more ‘needle-like’ aragonite crystals to be formed (which find it harder to stick to heat-exchange surfaces) than the normal calcite (which forms harder surface deposits).