Water softening

Salt is used to soften water. What is hard water and how is it treated?

When water contains a considerable amount of Calcium and Magnesium it is called hard. In Europe we can express the hardness of water in German Hardness or DH.

Hard Water is not harmful for our health but it can have some undesired effects. The minerals Calcium and Magnesium can precipitate as insoluble carbonates. The most common form of this is kettle stone.

To soften water a water softener is connected to the water supply. The softener contains an ion exchanger. An ion exchanger consists of a tank filled with beads of resin. Ions are connected to the ion exchange resin. These ions are exchanged with other ions from the surpassing water. When softening hard water flows through the bead of resin. The resin bonds the “hard” calcium and Magnesium ions and releases “soft” magnesium ions. The exchange capacity of the resin is not unlimited. After some time the resin is saturated with calcium and Magnesium. The resin has to be regenerated with a Sodium chloride solution. The Calcium and Magnesium ions are disposed of in the sewer. Softening of water can take place again.

Several types of salt are used for water softening. Eurosalt supplies, chucks, tablets and salt of different grain sizes for this application.