Why do you need a water softener?
Most of the water in US homes is hard water, meaning that it contains dissolved rock such as limestone and iron. Since municipalities are not required to filter out dissolved rock, water hardness is found in both private wells and municipal water. Dissolved rock is usually noticed as a white residue that is left on most surfaces that the water touches, such as glassware and hair. This residue buildup is also usually found in water-using appliances such as dishwashers and water heaters, possibly reducing the efficiency and lifespan of the appliance. If iron is in your water, it can often be seen as an orange residue that stains drains and toilets.
How do water softeners remove dissolved rock and iron?
Water softeners function using a process called ion exchange that utilizes plastic beads called resin to remove the hardness from the water. At the beginning of the softening process, resin beads have an ion of sodium or potassium attached that they exchange for dissolved rock or iron as it contacts the resin bead. The dissolved rock or iron is captured by the resin bead, and an ion – usually sodium or potassium – is released, effectively removing the hardness from the water. When all of the resin is saturated with dissolved rock, the resin is washed with a brine solution that makes the resin release the dissolved rock and exchange it again for sodium or potassium ions to begin the softening process again.