Water softeners use “ion exchange” to remove the minerals from your water. Ions are atoms with a positive or negative charge. If you remember high school chemistry classes, you’ll know that opposites attract and this is why salt is needed for your water softener.
Softener Resin 
Manganese, iron and other hard water minerals have a positive charge. This means in order to remove them you need something that carries a negative charge. Softener models contain a resin bed made using special polymer beads to provide this negative charge. As the water passes through the bed of resin, the positively charged minerals will be attracted to the beads and stick to the resin.
While this is an effective way to remove hardness minerals, the beads can become filled with mineral ions, and this is where salt comes into the mix.
Why Salt is Needed
Salt or sodium chloride is a magic ingredient to “clean” the resin beads. Sodium has a positive charge, while chloride has a negative charge. When the softener finishes a cycle, the salt in the rinse water is strong enough to pull the minerals from the beads and “clean” the resin bed. This allows those undesirable minerals such as manganese, iron, calcium, and magnesium to be flushed down the drain, leaving sodium attached to the resin bed.
This forms a continuous cycle. As water is passed through the softener, the dissolved minerals in your untreated water are exchanged with the sodium ions, until the beads are full of minerals. When this happens, another cleaning cycle is initiated.
There are two reasons why salt is used in most softener models. It is both non toxic and inexpensive, but also easily allows ion exchange without impacting the taste of the treated water.
So Does Softened Water Taste Salty?
If you’ve not had much experience with a water softener, you may assume that after ion exchange, softened water will taste salty. Fortunately, this is not the case. The quantities of salt involved in the ion exchange process are so small that it does not impact the taste of the treated water. In fact, the sodium content of treated water is lower than you would find in a slice of white bread. So, unless you are on a severely sodium restricted diet, softened water using salt should present no issues for you.
Is There an Alternative to Salt?
If you have concerns about using salt in a water softener, there is an alternative. Some softener models are equipped for ion exchange using potassium chloride. Unfortunately, there is a smaller selection of softener models that can use potassium chloride and the potassium crystals tend to be more expensive and less readily available compared to softener salt.
If you are considering a water softener, you should speak to a water treatment specialist. A fully WQA certified technician can not only assess your water quality, but guide you through the range of water treatment systems available on the marketplace that meet or possibly even exceed the industry standards.
With more than 25 years experience in the residential and commercial water treatment space, Terry is a WQA (Water Quality Association) certified water specialist, LEVEL 3, as well as a WQA certified sales representative. Terry currently sits on EcoWater Systems (a Berkshire Hathaway Company) national Peers committee, as a water treatment expert advising other water professionals with less experience on best trade and technology practices. EcoWater Systems of Nebraska is one of the biggest water treatment and water delivery businesses in the state.