What Is "Hard Water" and Should We Drink It?
As a child, I remember hearing my mother complain about the water being too hard. I don't remember which town we were in at the time, but the "hard water" meant we needed to use more laundry soap and more dish detergent, and my mother spent more time cleaning calcium deposits off the tub and taps. I wasn't terribly concerned about "hard water," after all, we could still drink it, wash in it, and swim in it, so I wondered why there was a problem.
Then, we moved to another town in a different province and were introduced to "soft water." The water tasted a bit odd, but that wasn't the biggest problem. It seemed that no matter how much we drank, we were still thirsty, even if we drank 'til our stomachs felt bloated. It took a while for our systems to acclimate, but our mother was thrilled with how little laundry soap, dish detergent, and shampoo we used.
What Is "Hard" Water?
So what exactly is hard water? What makes water hard or soft?
Hard water is said to be hard because of a high concentration of minerals in the water, most commonly dissolved compounds of calcium and magnesium, either as carbonates or sulphates. Water hardness is measured by how many parts per million (ppm) of the minerals are dissolved in the water.
Though there is no single international standard by which hardness is measured, water hardness classifications set out by the U.S. Geological Surveys are generally accepted.
Soft water has a high sodium content. It's wonderful for doing dishes, laundry and bathing, but though your iron and dishwasher may thank you, your body won't. Even in low concentrations, sodium makes it hard to quench your thirst as you are drinking, in effect, "salty" water. In fact, the salt (sodium) in the water will increase your thirst the more you drink.
Water Hardness Classifications
Parts Per Million or Milligrams Per Liter
Less than 17.1
17.1 - 60
60 - 120
120 - 180
What Causes "Hard" Water?
Hard water can be either temporary or permanent.
Temporary hardness in water is often caused by the presence of dissolved carbonate minerals (calcium carbonate and magnesium carbonate) leaching into the aquifer (water bearing strata).
This “temporary” hardness can be reduced either by boiling the water, or by the addition of lime (calcium hydroxide). Boiling hard water precipitates the calcium carbonate out of solution, leaving water that is softer when it cools.
Permanent hardness is usually caused by the presence of calcium and magnesium sulphates and/or chlorides in the water. These become more soluble as the temperature increases, and cannot be removed by boiling. Despite its name though, permanent hardness can be removed.
Both kinds of hardness, temporary and permanent, can be removed by installing a water softener, which will usually filter out most of the minerals suspended in the water.
Does "Hard" Water Cause Problems?
In domestic applications - in your own home - hard water can be a nuisance, but is generally not a serious problem. Hard water can cause water scale in your sinks and bath tubs, and unsightly rings in your plant saucers. Very hard water can also clog your pipes and prevent your dishwasher from operating at full efficiency.
If your water is very hard, you will notice, as did my mother, that you need to use more laundry soap, detergent, and shampoo. That is because the minerals in the water inhibit the soap from foaming or creating lather - the higher the mineral content, the harder the water, and the more soap you will need to use to make soap suds.
Sometimes, hard well water contains iron bacteria, which causes rust-colored staining along with the hard water scale. The bacteria can be removed by "shocking" the well with bleach, and is best done by a professional, or by adding an iron filter to your water softener. If you have iron bacteria in your water, I highly recommend using an iron filter, because the staining is made worse by hot water, and will permanently stain your clothes and linens, to say nothing of the mess it will make in your dishwasher.
In commercial applications, hard water can present a real problem. Hard water deposits (off-white scale) can clog plumbing. It can be deposited on the surfaces of pipes and heat exchangers, restricting the flow of water and compromising the efficiency of the heat exchanger, and in some cases, causing corrosion. Mineral deposits can also cause metal boiler components to overheat, and can cause the boiler to fail.
Installing and maintaining a water softener as part of industrial water treatment strategies will usually alleviate the problem, though in extreme cases, soft or distilled water may have to be piped in or trucked to the site.
Is Hard Water Safe to Drink?
Most towns and cities in North America and Europe have water treatment plants. As long as your water comes from a treatment plant, it should be safe to drink. Ground water from a well or cistern should be regularly tested, but unless the mineral content exceeds safety standards, and there are no other contaminants, your water is safe for drinking.
I can personally vouch for the safety of hard drinking water - in fact I prefer hard water over soft for drinking. I also prefer soft water for laundry, and bathing. This can be problematic, as most households only have access to one water supply - from the local town or city, from their well or cistern, or, in some parts of Northern Alberta, from a dugout (a man-made, open air cistern).
In fact, hard water is better for drinking than soft water, as soft water has a tendency to leach impurities from your pipes and faucets. It is possible to have the best of both worlds though. You can install a water softener and leave one dedicated cold water line for drinking water.
Water Treatment Worldwide
Water Hardness in France
How Do I Know What Kind of Water I Have?
Many states, provinces, counties, and municipalities have a web site, or a town office where you can access information about ground water or other water sources in your area..
Maps such as the one on the right, are often available for your location, showing what kind of water you have in your area.
You can also choose to have your water tested by a professional.
Water Softener vs Water Purifiers
Should I Treat or "Soften" My Hard Water?
We are fortunate to have a plentiful supply of clean, safe water in North America and in most parts of the world nowadays. Although the water in my town is certainly safe, we do filter our water for drinking and cooking.
We use a Britta water filter that simply screws onto our existing kitchen faucet. It cuts down on hard water scale in the glasses, the coffee maker and in our cooking pots. As well, we add about a cup of vinegar to the dishwasher's final rinse to combat water spots and scale build-up.
If you have a private well or dugout, you might consider a whole-home water treatment systems, which can run to thousands of dollars, and requires professional installation. These systems most often include a pressure tank, various filter tanks, and a water ion exchanger (softener), and require careful and ongoing maintenance. Purchasing water may actually be more economical.
If you do decide that treatment is your best option, get recommendations from friends and neighbors wherever possible, especially if they have the same type of water as you. Do your homework - research your options carefully before deciding on a method or a company.
Common Water Treatment Systems & Costs
Type of Filter
How it works
Level of Filtration
Water is diverted through a filter on your tap
Removes most odors (chlorine) and some impurities (such as sediment)
Britta: $19.99 - Pur: $15.99
Water is poured in a vessel (pitcher) and sinks through a filter (usually activated charcoal)
Removes most odors, tastes, and some impurities (such as chlorine and calcium)
Britta: $19.99 - Pur: 29.97
Often installed under sink. Water from taps is diverted through the filter system before dispensing
Removes most odors and impurities, as well as filtering out some contaminents.
Aquasana AQ-4600: $186.99 - Cuno Aquapure AP DWS1000: $548.92
Some helpful links
- Understanding Home Water Treatment Systems
MU Extension, University of Missouri - Understanding Home Water Treatment Systems
- CDC - Water Treatment - Public Water Systems - Drinking Water - Healthy Water
Education and information about water treatment, community water treatment, water systems, public drinking water, safe drinking water, coagulation, flocculation, sedimentation, filtration, disinfection, community water fluoridation, fluoridation, con
- NSF Consumer Information: Home Water Treatment Devices
Information about selecting and using a home water treatment device.
A good place to start your research...
- Best Water Filter Reviews
Compare Water Filters: Research top brands of water filters at waterfiltercomparisons.com
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