What is Hard Water and Water Softening
We call water "hard" if it contains a lot of calcium, magnesium or other minerals. Groundwater acquires these metals by dissolving them from surrounding soil and rock.
Hard water causes two problems:
- Dissolved calcium and magnesium precipitate out of hard water as scale, which builds up on the insides of pipes, water heaters, tea kettles, coffee makers and industrial machinery. Scale reduces flow through pipes and is a poor conductor of heat. Eventually, pipes can become completely clogged.
- Hard water reduces soap's ability to lather, whether in the shower, sink, dishwasher or washing machine, and reacts with soap to form a sticky scum.
Water softening is the removal of calcium, magnesium, and certain other metal cations in hard water. The resulting soft water is more compatible with soap and extends the lifetime of plumbing. Water softening is usually achieved using ion-exchange resins.
See How A water softener works.