Hard water is made up of calcium and magnesium that cause scale build up. Appliances running on hard water begin to loose efficiency and require repair or replacement more often. Limescale is hard to clean, often requiring harsh chemical and abrasives to remove it. Hard water limescale build up can be treated in three different ways: with an Aqua Systems Gen II water softener, or with a sacrificial resin system that is salt free, or with the Vulcan Electronic Descaler.