The ActivFlo from ZilmetUSA is a No-Salt Hard Water Conditioner. Hard water is a common water condition that is a result of calcium and magnesium in the water supply. Effects of hard water include limescale buildup, reduced water flow, reduced heating efficiency, and waste of detergents to clean. The Activflo imposes a catalytic action as water flows through, that causes calcium to form into an insoluble aragonite crystal. These crystals do not have the same bonding properties as calcium which means they won't stick to pipework, heating elements, faucets, etc.