Limescale buildup can reduce the effectiveness of your dishwasher. Finish Salt features 5x POWER ACTIONS and has a grain size specially developed for use in dishwashers. The pure salt ensures that the dishwasher’s anti-scale function works effectively and protects against limescale buildup. The salt also helps provide effective protection against water spots and streaks on glass and china. Important to know: other salt products may contain impurities such as iron or carbonates that can damage the dishwasher’s anti-scale function.