The Water Softener is the most common tool used in the removal of scale-forming calcium and magnesium ions (known as temporary hardness) from hard water. In many cases, a water softener can also be used to remove ferrous (soluble) iron from a supply. A standard water softener works by allowing hard water to filter downwards through a bed of ion exchange resin. The ion exchange resin attracts the calcium and magnesium ion (hardness) and replaces them with sodium ions which are less problematic for water systems and will not cause scale build-up. Once the ion exchange resins are saturated with hardness, the regeneration of resin bed is carried out by passing NaCl solution (Common Salt) through the resin bed to activate the resin to put the system back in operation.