About water softening equipment

Water softeners are appliances connected to your home’s water supply that remove the minerals like calcium and magnesium that cause water hardness. Water softening equipment can be easily removed, so you can take it with you if you move.

The most common method for producing soft water is through ion exchange, a process in which the calcium and magnesium in the water are exchanged for another element, usually sodium. Sodium won’t cause lime scale or soap scum buildup like other minerals do, and water softening adds only a very small amount of sodium to your water. According to the Mayo Clinic, an 8-ounce glass of soft water would have less than 12.5 milligrams of sodium, which is considered “very low sodium” by the Food and Drug Administration.

How a water softener works

How Water Softeners Work

A water softener has two tanks: a mineral tank and a brine tank. The mineral tank is where the actual ion exchange, or water softening, takes place. It’s filled with small, negatively-charged polystyrene beads called resin or zeolite. The brine tank is where the sodium, or salt, is stored and mixed with water.

As hard water passes through the mineral tank, the beads inside attract the positively-charged calcium and magnesium ions. The minerals that cause hard water stick to the beads, and the treated water goes out into your home’s plumbing system.

Over time, the beads become coated with minerals and have to be cleaned. This cleaning process, called regeneration, has three cycles: backwash, recharge and rinse. The regeneration process can be scheduled automatically with an electric timer, through a mechanical water meter, or a computer.

In the backwash cycle, the water softener’s control valve reverses the flow of water though the tank to flush out any debris. Then, the recharge, or regeneration, cycle begins. During the recharge cycle, the brine solution gets pumped into the mineral tank. Since the salt solution has a positive electrical charge, it’s attracted to the negatively charged plastic beads. The salt ions force the calcium and magnesium ions off of the beads, and then the brine, magnesium and calcium are all flushed out of the mineral tank. The tank is then rinsed and filled with water. The beads covered with salt now, but it’s so diluted that it has a weaker electrical charge than the calcium and magnesium, so the sodium is forced off the beads and into the softened water and the whole process repeats itself.

Image credit: PopularMechanics.com

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