This expert, unbiased water softeners report will help you choose the right size water softener, understand salt-free and dual-tank softeners, and more.
Hard water is simply water that is rich in minerals such as calcium, magnesium carbonate, and manganese. If you find that soap and shampoo don’t lather well, dishes are spotted, the bathtub has a ring, laundry is dingy, and the coffee maker has scale deposits, your home probably has a hard water problem.
Though these minerals are natural and not typically hazardous to health, they can create deposits in your plumbing, water heater, and other water-using appliances, and make washing dishes, clothing, skin, and hair more challenging.
Hard water is a familiar reality for millions of Americans. According to the U.S. Geological Survey, 85 percent of American homes have problems with hard water.
Solving Hard Water Problems
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). One 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 up 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. You can buy a water test kit online.
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 percent to 30 percent 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.
Hard water does enter the health arena in one area: People who have hard water are more prone to rashes and skin problems because it changes the skin’s pH so that soap remains on the skin, clogging pores.
Types of Water Softeners
By far the most popular and commonly used type of whole-house water softener is an ion-exchange or “cation exchange” unit, but a couple of other technologies are also available. It’s important to understand the differences.
Salt-Based Ion Exchange Softener
This type of water softener cycles household water through two tanks: one with special resin beads and the other filled with brine. It works on the principle of ion exchange, softening hard water by substituting sodium (salt) for hard minerals such as calcium, magnesium, and iron. For a complete explanation of how a conventional water softener works, please see How a Water Softener Works.
Salt-Free Water Softener
A salt-free water softener regenerates with a potassium-chloride salt substitute rather than sodium. This type of unit may be a better option for people who are concerned about salt intake. This type of water softener is actually a descaler—it doesn’t reduce the hard water minerals but rather prevents minerals from being deposited as scale to the surfaces of water-using appliances and pipes.
The general consensus is that this type of water treatment is better than no water softener at all, but not as effective as conventional water softening. For more, please see the articleSalt-Free Water Softeners.
Dual-Tank Water Softener
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 with 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 break in service. 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.
Magnetic Water Softener or Descaler
In the Salt-Free Water Softeners article, you’ll also find a discussion of a more controversial option—the electronic or magnetic water softener or descaler. 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. Please see the article for more about this.
If you would like to try out one of these, please check out and read the user reviews for the Eddy Electronic Water Descalershown here—available on Amazon. Note that the manufacturer offers a 12-month money-back guarantee. If you do try it out, please send us your feedback.
Water Softener Size & Features
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.
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.
Water Softener Controls
Before leasing or buying a water softener, become acquainted with its features:
Check out what controls the regeneration cycles, how long each cycle takes, and how much water and salt are used for recharging. Be aware that even fully automatic types require occasional refilling with salt. Several different methods are used for controlling cycles, but the two main types are:
Water softener timer controls. Clocks or electronic timers automatically recharge the unit at a preset time and day, based on your average usage. This type may fall short if you have unusually large water usage on a particular day. They also waste sodium and water because they regenerate whether or not recharging is necessary. They usually do this in the early morning hours.
Softener DIR controls. A more sophisticated method, called demand-initiated regeneration (DIR), senses when the resin must be recharged, either electronically or with a meter that measures and calculates usage. A demand-initiated regeneration system saves on salt and regeneration water because it does not recharge unless necessary. In addition, it provides for abnormally large water usage.
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 service person is required to do the job. And be sure to pay attention to the monthly fee for 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 waste water 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.