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Water softeners, or conditioners, are often used to turn hard water into soft water. This is typically accomplished by replacing the ions of calcium and magnesium in hard water with sodium ions. The salt free water conditioner is an alternative to this method. Two common salt free processes include lime conditioning and physical conditioning. The first involves adding lime to water, while the second will usually use a powerful magnetic field to change the character of the water. While these types of water conditioners do not remove any hard minerals, they may reduce many of the undesirable effects associated with hard water.
Hard water by definition contains ions of calcium and magnesium, which are sometimes referred to as scale. These minerals can form deposits in pipes, on fixtures, and in hot water heaters. They may also also cause soaps and shampoos not to lather properly. True soft water contains little to none of these ions, while traditionally softened or conditioned water will contain sodium ions instead. Both naturally soft water and artificially softened water will allow soap and detergents to lather while not leaving scale or scum buildup behind.
Lime softening actually removes the hard minerals from the water, rather than replacing them with different ions. This method was first used used in England in the mid-1800s, and continues to be used in areas like the midwestern U.S. It can also remove other dissolved solids, which may or may not be desirable. For instance, lime softening may also be used to remove things such as arsenic and radium from water sources.
Physical conditioning typically uses a strong magnetic field to change the properties of hard water. These salt free water conditioner systems do not remove the mineral ions from the water, but have been reported to make water feel softer. They may also help reduce scaling in sinks and other fixtures where water is not allowed to sit. Since the minerals are still present in the water, scaling may still occur in other locations, like hot water heaters.
Another type of salt free water conditioner is chelating agents. These materials are typically not used to soften municipal water sources or well water, but may be included in products like detergents. Citric acid is one such substance that is often included in laundry detergent to soften water during the wash.
While not technically a salt free water conditioner, potassium chloride water softeners do not add sodium ions to the treated water. These systems use potassium ions instead. Potassium and sodium are both salts. Though many people get too much sodium from their diets, many need more potassium. For instance, two liters (67 ounces) of water softened with sodium ions may contain roughly 480 mg of sodium, which can present a problem for those watching salt intake. Replacing that sodium with potassium can provide valuable potassium to the diet, while still softening the water.