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Hard Facts About Hard Water

Soft and hard water behave differently, from cleaning power to corrosion potential

Apparently, all tap water is not created equal.


Some water is deemed "hard," and other is considered to be "soft." And here's the confusing part: Hard water isn't better than soft in all situations, and soft isn't always preferable.


Confused yet? We explain the ins and outs of each below.

Soft water: Contains few or no extra elements. It can be naturally occurring, or produced with water treatment devices that remove hardness elements, such as calcium and magnesium.

The basics


Hard water: Contains relatively high amounts of calcium and magnesium. This happens

when the water comes in contact with rocks or soil. In the United States, 85 percent of the water is hard, according to a U.S. Geological Survey.



Hard water: Certain minerals in the hard water interact with the soap or detergent, which keep it from interacting with soils, stains and dirty dishes.


Soft water: Softened water reduces the need for detergent by more than 50 percent because it doesn't contain the minerals that interact with the cleaning products. Washing in the cold water setting instead of the hot water setting achieves the same or better stain removal compared to results in hard water, according to a 2011 study conducted by the Scientific Services S/D Inc, a New York-based laboratory focused on testing laundry detergents.




Hard water: Makes soap less effective, and creates scale and film buildup in showers, requiring increased frequency of cleaning, and increased use of chemicals to clean the shower walls and tubs.


Soft water: Soap lathers easily with soft water, making it effective for body washing. But from a health perspective, it doesn't matter.




Hard water: From a health perspective, the presence or absence or hardness is neutral because hardness doesn't negatively impact health.


Soft water: Aids in cleaning and prevents deposits left on pots, pans and dishes through the evaporation of hard water when boiling or baking.


Energy consumption


Hard water: For gas water heaters, every 5 grains per gallon of hardness causes an 8 percent loss in efficiency, and an 8 percent increase in cost when using 100 gallons of hot water per day. (Hardness is measured in grains per gallon as calcium carbonate; 1 grain equals 17.1 milligrams per liter.)


Soft water: It responds to detergents and soap more effectively than hard water does, cutting overall energy costs.


Excessive hard and soft


Hard water: Excess hardness can cause scaling inside your pipes, water heaters, coffee makers and even industrial machinery. The scale restricts the flow through the pipes and is a poor conductor of heat. Eventually, your pipes can become completely clogged.


Soft water: When the hardness of the water is too low, it can deteriorate metal equipment used in swimming pools (hand rails and ladders), contribute to staining of concrete, vinyl and fiberglass materials and reduce the effectiveness of chlorine.


Switching sides


Hard water: There are several ways the hardness of water can be reduced, including distillation, reverse osmosis or the addition of a chemical softener, which is most common. Conventional water-softening appliances depend on an ion-exchange resin in which hardness ions are exchanged for sodium ions. Look for a water softener that's certified to national standards such as NSF/ANSI 44.


Soft water: Calcium chloride is often used in pool maintenance to increase the hardness of water in the pools.

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