What is Water Softener Salt?

Water softener salt is a product that removes ions from water that make water hard. Hard water refers to water with above average mineral content. This typically means calcium (Ca) and magnesium (Mg). Higher amounts of dissolved calcium and magnesium in water make the water less able to dissolve other solutes, such as soap. Hard water can also lead to clogged pipes due to increased lime scale build-ups. Lime scale build-ups make heating less efficient and produce more wear and tear on pipes and water dependent household machines, such as dishwashers and laundry machines.

Companies and households soften water to reduce heating bills and maintenance costs for piping and machinery. A water softener salt is designed to extract positively charged ions, namely calcium (Ca2+) and magnesium (Mg2+), though softeners are sometimes used to remove iron as well. For example if the salt sodium chloride, or Na+Cl-, is introduced into hard water, the salt will break apart, or ionize, and readily bind with negatively charged ions. This will leave free sodium ions (Na+) or sodium bicarbonate in the water while the chloride ions (Cl-) would bind with the positive magnesium and calcium ions to produce CaCl₂ and MgCl₂. The amount of dissolved calcium and magnesium ions is thus decreased, while the sodium ion content rises.

There are three types of water softener salt in general use: rock salt, evaporated salt, and solar salt. Rock salt is a naturally occurring salt found as a mineral in underground salt deposits. Rock salt is mostly sodium chloride, though it has small amounts of calcium sulphate as well. Evaporated salt is also found in underground salt deposits, though in dissolved form. The water is then evaporated from the salt, leaving almost 100 percent sodium chloride. Solar salt is obtained through seawater evaporation and contains roughly 85 percent sodium chloride.

Rock salt is the cheapest of the three water softener salts on the market, but because it has a higher insoluble composition, the softener reservoir needs more frequent cleaning. Solar salt, though better than rock salt, has more insoluble components than evaporated salt and requires more reservoir cleaning. If the water is harder and requires more salt usage, evaporated salt is recommended. While it is not harmful to mix these salts, it is preferable to use one type of salt at a time to prevent clogging.

The salt reservoir should be checked monthly to ensure that the water softener salt level is at least half full. One should not expect to see immediate softening results after adding salt softeners, as the salts take time to dissolve. Purchasers should be wary when buying a water softener that salt is corrosive and can break down pipes over time. Also, salt-softened water may not be suitable for babies due to the high sodium content.

Generally, the sodium found in water after using water softener is not present in high enough concentration to raise any health concern, but if a person is on a low sodium diet or for another reason wishes to reduce sodium intake, there are other options. Filters can be set up to remove salt, but this is usually very costly, so they are usually installed just at drinking faucets. Sodium chloride salt can also be replaced with potassium chloride salt.