An unbiased, expert consumer review and report on how to buy the best water softener system for your home.

By Don Vandervort, HomeTips

Hard water comes from aquifers and other underground sources that collect dissolved minerals from rock—particularly calcium, magnesium carbonate, and manganese. These minerals give water undesirable characteristics that collectively are dubbed “hardness.” The severity of hardness is measured by grains (of mineral) per gallon (GPG) or, in some cases, by parts per million of mineral (PPM). 1 GPG equals 17.1 PPM.

Technically, any water that contains more than 1 GPG of dissolved hardness minerals is considered hard, but, realistically, water with from 0 to 3.5 GPG is relatively soft. Water with more than 10.5 GPG is very hard. Between these extremes is typical, moderately hard water.

Hard water is less an issue of health than of potential expense. Many of the problems created by hard water are hidden until some type of malfunction occurs in your home’s plumbing system or in a water-using appliance. When heated, dissolved hard-water minerals recrystallize and form scale that eventually clogs plumbing, reducing water flow. Scale and lime deposits also take their toll on water-heating appliances such as dishwashers and coffee makers, increasing the need for repairs.

Worse yet, scale cakes onto interior surfaces of water heaters, making them more likely to fail. According to a study commissioned by the Water Quality Research Council at New Mexico State University, water heaters operate 22%–30% less efficiently when plagued with hard-water scale.

Hard-water problems are more obvious as a nuisance when you bathe and cook, do laundry and clean house. Calcium and magnesium react with many soaps, shampoos, cleansers, and detergents, diminishing their lathering and cleaning capability so you have to use more and rinse longer. They also form a scum on tile and what appears as bathtub ring that is difficult to rinse away. In the kitchen, this “soap curd” translates into spotted dishes and scale on cookware. Additionally, certain hard-water minerals, such as iron and manganese, can give water an undesirable appearance, odor, or taste.

Why we like it: • Generous flow rate of 16 gallons per minute • Treats water for the entire house • Salt storage capacity of 300 pounds

Hard water does enter the health arena in one area: People who have it are more prone to rashes and skin problems because it changes the skin’s pH so that soap remains on the skin, clogging pores.

Selecting Water Softener Size & Capacity

When buying or leasing a new water softener, selecting one that is the right size is important. You'll want to get one that can handle the demands of your household but is not unnecessarily large (and expensive). Physical size isn't the issue—the unit’s ability to remove “hardness” minerals from water without frequent regeneration is. (For more about regeneration, see How a Water Softener Works.)

Water softeners are sold in several sizes, each rated by the number of grains of hardness they can remove from water between regenerations. The idea is to get a unit that will go at least three days between recharges. Ideally, the water softener can also handle periods of larger-than-normal water usage.

You can calculate the size of water softener your family needs by multiplying the number of people in your household by 75—the average number of gallons used per person per day—to figure out the total amount of water your household uses daily. Then multiply this number by the number of grains per gallon (GPG) of hardness minerals in your water to figure out the capacity of whole-house water softener you need.

So, for example, if you have a family of five, figure 375 gallons of water are used per day (5 X 75). If your water has 10 GPG, you have 3,750 GPG of hardness minerals (375 X 10) requiring removal each day. 

   Grains of Hardness to Be Removed Each Day

Salt-Free Water Softeners

Some people are concerned about the health effects of the sodium that softeners put in water. Be aware that most health concerns are over intake of sodium chloride, not the sodium bicarbonate that results from softening water. In addition, opinions expressed in the New England Journal of Medicine minimize concerns about the amount of salt introduced by water softeners.

Although the amount of sodium added is minimal compared to a healthy person’s normal diet, people who have been advised by a doctor to reduce sodium intake may want to consider a unit that regenerates with a potassium-chloride salt substitute rather than sodium.

Another option is to bypass one or more cold water faucets in the house that are used for drinking water. Some people connect a standard unit only to the hot water side of the water supply system; unfortunately, with this option, you forfeit some of the benefits of having soft water in the shower, laundry, and wherever else cold water is mixed with hot since only about half of the water is softened.

Another option is to install a reverse-osmosis water filter that will remove salt from drinking water. For more about water filters, see Types of Drinking Water Filters.

A more radical—and controversial—option is an electronic or magnetic water softener. According to manufacturers, this plug-in device, which clips onto the incoming pipe, sets up a magnetic field that changes the electromagnetic properties of the calcium-carbonate minerals so they are repelled by pipes and each other.

A study commissioned by the Water Quality Association, however, found that, when such devices were tested against conventional ion-exchange softeners and against claims made by the manufacturers, no significant physical or chemical changes in the water occurred and the units did not reduce scale formation. Despite the effectiveness claims made by manufacturers of these devices, buyers should beware.

Dual-Tank Water Softeners

When a water softener is recharging, it is designed to disconnect from the water system, so it is basically out of commission. For this reason, the regeneration cycle is usually set to occur at night. If softened water is needed during the regeneration cycle, this can be problematic.

If the down time of the water softener is an issue, or if a family is large or lives where water is particularly hard, it may be smart to consider a dual-tank water softening unit that has two resin tanks. With a dual-tank unit, when one tank is in use, the other is regenerating. As a result, softened water is being supplied continuously, without any down time. And because these units operate on demand, they can be sized smaller than single-tank units.

Several models are available. One popular product, the Fleck 9000, has a fully adjustable valve that is controlled by a meter. When the water softener starts backwashing one tank, its control switches the water supply to the other tank, offering a continuous flow rate of 21 gallons per minute. With this model, you can buy various tank capacities—24,000-, 32,000-, 40,000-, 48,000-, 64,000-, 80,000-, and 110,000-grain capacity per tank. These range in price from $950 to $2,000.

When shopping for a dual-tank water softener, keep in mind the space it will require. It should be installed where it can serve the main inbound water line so it can supply the entire house. It will also require a drain for backwashing. If you choose a model that requires electrical power, a circuit will be required nearby. For more about placing your water softener, see How to Install a Water Softener.

Also look for features such as NSF (National Sanitation Foundation) certification and a solid warranty on the control valve and mineral tank such as three years for the valve and 10 years for the mineral tank. A good water softener should last at least 20 years.

Water Softener Buying & Leasing Tips 

Should you buy or lease a water softener? In the short run, leasing is often the most attractive option because there are no significant upfront costs. Depending on the level of service and materials the company offers, you can pay from $15 to $50 per month or more on a lease. If you buy, you will pay about $150 per year for materials. And, of course, you’ll have to pay for the unit. Depending upon the features, prices range from about $400 to $2,500 or more.

Get at least two quotes. And be sure the quotes are based on exactly the same type of considerations: regeneration cycle, type of controls, level of service, and, of course, warranty on both the control valve and the resin tank.

It is usually best to work with an established company. That way, you’ll get a quality product backed by a company that is likely to remain in business for a while.

Find out whether you will need a plumber for installation or whether a special factory serviceperson is required to do the job. And be sure to pay attention to the monthly fee of maintaining the softener.

Some softener firms provide a service where they regularly exchange exhausted with charged units. This type of service is a good bet if you live in an area where wastewater from sewers is recycled for municipal watering because sodium may be considered a pollutant. 

Also look for certification. NSF International is an independent testing organization that tests and certifies water-treatment products. The water industry’s trade organization, the Water Quality Association, also certifies equipment, so look for the WQA Gold Seal. Although neither of these certifications guarantees performance, they signify that the equipment has successfully passed testing for industry standards and the manufacturer’s claims have been validated—an important step toward ensuring that the unit you buy or lease will offer years of trouble-free service.