The Hard Truth About Hard Water

If your customers don’t understand how hard water affects their plumbing, give them this basic tutorial.
The Hard Truth About Hard Water

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No doubt your customers have heard of hard water. But that doesn’t necessarily mean they understand it and what to do about it. Here’s some information that may help you address common customer questions:

1. What Is Hard Water?
Hard water is water that has a high level of dissolved minerals in it, especially calcium and magnesium. The quantity of minerals varies from source to source, and hard water can be found in municipal water systems as well as private wells. The water treatment industry measures hard water in grains per gallon (gpg). Water Quality Association guidelines for measuring hard water are:

Degree of Hardness Grains Per Gallon (gpg)
Soft < 1
Slightly Hard 1.0 - 3.5
Moderately Hard 3.5 - 7.0
Hard 7.0 - 10.5
Very Hard > 10.5

Sometimes water testing is reported in mg/L. You can convert mg/L to gpg by dividing the mg/L by 17.1.

2. Is Hard Water Dangerous?
It is not dangerous to drink, but it can lead to other problems. According to the Water Quality Association, hard water originally got its name because it is hard to wash with. The minerals in the water prevent soap from lathering. If you wash your hands using very hard water, your skin may feel as though it is covered with a film. Other problems include:

  • Stains in the sink and on dishes and glasses.
  • Clothing and other fabrics that look dull and wear out more quickly than they should.
  • The buildup of scale that can appear on faucets, clog pipes and reduce water pressure, and force appliances like water heaters to work harder, reducing their energy efficiency. 

3. How Can I Find Out If I Have Hard Water?
If homeowners experience some of the problems listed above, they may suspect that they have hard water. But even in obvious cases, the water needs to be tested. The tests will not only confirm a suspicion of having hard water, but they will also pinpoint the extent of the problem, or how many gpg the water contains. This is important because knowing the gpg count is vital when sizing a water softener to solve the problem.

Homeowners who are part of a municipal water system can consult the "Consumer Confidence Report," sometimes called the "Water Quality Report." The report is a requirement of the Clean Water Act and requires municipal water facilities to test the water they supply to the public. The utility must then mail a copy of the report to its customers once a year. The requirement is for any water company that serves more than 25 people or 15 households. Copies of reports are usually available from the water company or the local regulatory agency. Many towns post a copy of recent reports online.

Homeowners who use a private well should have the water tested. Unless they are planning on testing for contaminants, hard water tests are relatively inexpensive.

4. What is a Water Softener?
Water softeners remove the minerals that contribute to hard water before the water circulates throughout the house. Softeners are usually installed near where the waterline enters the house. They consist of two components: a resin tank and a brine tank. The softening process goes like this:

  • Water flows into the resin tank.
  • The minerals in the water attach themselves to the resin.
  • The resin, in turn, gives up a sodium ion in the exchange.
  • The softened water flows out of the tank and to the faucets throughout the house.

After a period of time, usually four to 10 days, the resin must be regenerated. That means:

  • Liquid from the brine tank flows into the resin tank.
  • The solution exchanges new sodium for the minerals attached to the resin.
  • The solution, which now contains the hard water minerals, is flushed down a drain.
  • The system is ready to repeat the process.

Because the softening process stops during the regeneration cycle, regeneration usually occurs in the middle of the night. 

5. How Do I Choose the Water Softener That Is Right for Me?
Water softeners are sized based on how many grains of minerals they can remove before it is necessary to regenerate the resin. You will see products listed as a 32,000 grain, 40,000 grain, etc. To determine a household's needs, multiply the number of people in the house by the amount of water they use in a day — most people use 75 or 80 gallons per person per day. Then multiply that number by the gpg in the water. Say there are four people and the water is at 10 gpg. Four people times 75 gallons equals 300. Multiply that by 10 gpg and you get 3,000 grains per day. If you assume the system regenerates once a week, this house needs a system that can remove 21,000 grains.

That is sizing in its simplest form, but there are often other things to consider. In the example above, a 21,000-grain system appears to be perfect. But suppose in order to remove those 21,000 grains, the system uses 15 pounds of salt. Then it may be a good idea to check the specification on a slightly larger system. The larger system may be able to remove 21,000 grains using half the amount of salt. It can do this because it has a larger resin bed. The homeowner will pay more for the larger system, but they will also save in salt and won't need to replace the salt as often. The tradeoff may be worth it to the homeowner.

Some other things to consider when selecting a water softener:

  • Some softeners offer the choice between timed regeneration and on-demand regeneration. With timed regeneration, the process takes place based on a programmed schedule. With on-demand regeneration, the system regenerates when needed. On-demand regeneration is more efficient.
  • Low-salt indicators signal when the system is getting low on salt.
  • You may want to talk to a customer about installing bypass valves so the water softener can be serviced without interrupting water flow to the house.
  • The system will require electrical service nearby, as well as a drain to flush away the hard water waste.

About the Author
Fran Donegan writes home- and garden-related content for numerous digital and print publications. He is the author of the books Pools and Spas and Paint Your Home. Donegan also writes for Home Depot, which offers a wide selection of water filtration and softening options.


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