The Aquios Salt Free Water Softener is a revolutionary, natural approach to preventing the damage and problems caused by hard water. While our other systems provide both water conditioning and water filtration, the AQS400 is designed for water softening only. By utilizing a natural, food grade additive that is safe and proven to be effective, the Aquios system will prevent and inhibit calcium scale from forming as well as providing protection against corrosion. In addition, the healthy minerals your body needs are not removed or replaced with salt.