A water conditioner is a general term for a piece of equipment that changes the water in your home in some way. A water conditioner might filter, remove chlorine or improve taste of the water. A water softener is a specific type of water conditioner that reduces water hardness one grain per gallon or less.
Hard water contains dissolved ions of calcium or magnesium. These ions occur naturally as water runs through limestone deposits on its way to your house. If you have hard water in your home, you might notice a whitish film on your glassware. You may have to use more soap than you would in a house with soft water. This happens because the dissolved minerals inhibit the soap.
A home water softener works by swapping calcium and magnesium for another ion. Inside the softener, water runs over a bed of tiny plastic beads that are covered with sodium or potassium ions. The water releases its calcium and magnesium and picks up sodium.
A water conditioner can work in a variety of different ways. It could use carbon filtration, electromagnetic waves, magnets or ceramic media to remove particles. There is no set standard for how “pure” a conditioner must make the water, and there is controversy over whether some conditioning methods really work.
Some water conditioners add an ingredient like chlorine to filtered water to kill any bacteria that may be living in the water. In the United States, water supplies are usually safe enough for the general population. If you live in an area where groundwater is often contaminated or if someone in your family has a compromised immune system, then a water conditioner with disinfectant might be beneficial.
The minerals in hard water not only create a film on dishware, they can also leave their sediment on the inside of pipes. When the sediment gets thick, it can affect water flow through the pipes. When the sediment builds up around a heating element — in a boiler, for example — it acts like insulation and prevents the heating element from doing its job of heating water. When the heat can’t dissipate into the water, it builds up on the element and can cause overheating and breakage. In very hard-water areas, water softeners can help plumbing and boilers last longer.
In areas with a lot of dissolved particles in water, a water conditioner can make water look clearer and taste better.
Water softeners and conditioners can get expensive. In many cases, they aren’t even necessary. Calcium and magnesium do not pose any proven health risk, and community water supplies in the United States generally don’t require disinfection.
Softened water reacts with soap to produce more lather. If you are used to hard water, it may seem like it takes forever to get soft-water soap suds out of your hair and laundry.
Many water softeners exchange hard minerals for salt, which increases the salt content of drinking water. This could present a health risk for people on salt-restricted diets.