On a recent episode of Jeopardy!, the correct response to one clue was “What is hard water?” That would have been a gimmee to many of us from rural areas. But apparently, that day’s contestants had never opened a tap that wasn’t connected to a municipal water supply. Nobody even buzzed in. My inner curmudgeon wondered how people who know so much about history, music, literature, and pop culture could not know this.

In the U.S., each person uses an average of 82 gallons of water a day at home. About 85% of that water contains large amounts of dissolved calcium, magnesium, and other minerals. We may never make it onto the Jeopardy! stage. But just in case, here are some hard truths we should all know about hard water.

Not that kind of hard. Where winters are so long that ice fishing is a high school team sport, “hard water” is the punchline to a number of Dad Jokes. But we’re not talking about liquid changed to a solid state. Hardness in water refers to the amount of dissolved minerals, primarily calcium and magnesium, picked up as water percolates through rocks and minerals before it’s pumped from your rural well to your faucets. Soft water, by contrast, contains fewer (or at least different) dissolved minerals. 

It can taste great. Okay, some hard water has off flavors, and people accustomed to flat, chlorinated city water might think hard water has a chalky taste. But many of us get the equivalent of fancy bottled mineral waters straight from the tap. At my home in rural northern Wisconsin, our well has what I think is the best water in the world. When Bill and I have been away, the first thing we do when we return is drink a big glass of cold water straight from the faucet. For that thirst-quenching sweetness, I’m willing to overlook that the glasses we use are always water-spotted.

Dissolved minerals precipitate. When a solution containing dissolved minerals evaporates, those minerals return to a solid state – like those spots on glassware. That solid state, unfortunately, builds up and can lower the efficiency and reduce the useful life of your plumbing, water heater, and fixtures. It becomes a calcium crust (a.k.a. lime scale) on your shower head and the nozzle that flows water onto grounds in your coffee maker. When you walk into a rural home that smells strongly of vinegar, it doesn’t necessarily mean someone is making pickles. It might just mean the coffee maker has been brewing so slowly that someone is running a pot of vinegar through it, using that mild acid to help dissolve the mineral particles. Then again, I have to add a splash of vinegar to the water when canning so my jars aren’t coated with a hazy lime scale that doesn’t wipe off. So it could be pickles after all.

“Scum.” Soaps and detergents react with the calcium in hard water to form a stubborn residue on showers, basins and tubs. As a mild oath, “pond scum” implies a person or thing perceived as worthless or contemptible. But when the term “shower scum” is loosed, it means (roughly): “more disgusting than zombies with the sticky persistence of bubble gum, bug tar, tree sap, asphalt, or taffy on the dash of a hot car”. Social etiquette with rural relatives requires 48-hour notice prior to an overnight stay so the host may attempt to clean the shower before your arrival. By contrast, when we visit folks with soft water, we may spend a lot of time in the shower but it’s not because we’re admiring the absence of soap scum. It’s because the amount of shampoo we would use at home produces enough lather for a Prell commercial. It’s because there’s no squeak in squeaky clean, no minerals in solution holding on to a film of shampoo or body wash. In softer water, we just don’t know when the rinse cycle is complete.

Laundry woes. Hard water also interacts with laundry agents. To get clothes clean in hard water it generally takes a bit more detergent and possibly hotter water, which can shorten the life of fabrics that still go gray or dingy anyway. When I was a kid we weren’t Catholic and didn’t know about patron saints or my mother would have prayed to Hunna, patron saint of laundresses. Mom grew up in a house without indoor plumbing and never took a drop of water from the tap for granted. But she hated dingy whites and sheets that turned orange from the iron in our hard water. When my parents finally achieved a measure of financial stability, they didn’t celebrate with a new car or a vacation: They got a water softener. 

Water softeners. Household water conditioning systems remove unwanted substances – like minerals. Reportedly, they save you money by extending the useful life of appliances and plumbing and because you use less soap and detergent. I’ve also heard they contribute to brighter laundry, shiny/bouncy hair, and happy marriages. Bill and I have always needed something else more than a household water conditioning system, so we don’t have one. I suspect some of my neighbors do, based on observations of their dazzling whites and lustrous tresses. But we live where you can wear a hat for all but about six minutes out of the year and not even soft water can keep you from having hat-hair. We’re good.

Testing, testing. Recently, we had to replace our 20-year-old washer. The new one came with a sheaf of coupons for laundry products I’d never heard of. It also included a free hard water test strip, which I couldn’t wait to use. I filled a water-spotted glass, dipped the strip for three seconds, and waited 20 seconds for the color to change. Then I compared it to a control chart to see approximately how soft or hard our water is as measured by milligrams of calcium carbonate to liters (mg/L). That measurement generally translates like this:

  • 0 to 60 mg/L is classified as soft
  • 61 to 120 mg/L is moderately hard
  • 121 to 180 mg/L is hard
  • more than 180 mg/L is very hard. 

While the test didn’t tell me much I didn’t already know, I bet some former Jeopardy! contestants might have buzzed in if somebody had even given them a free hard water test strip.

Lifelong learning. Even beyond activities of daily living like laundry, dishwashing and bathing, learning how hard water affects things is a lifelong process. My husband kept a 55-gallon freshwater aquarium for years. Fish and aquatic plants are sensitive to General Hardness (GH), Carbonate Hardness (KH – dissolved carbonates and bicarbonates), and pH (hydrogen ions, which indicate how acidic or alkaline the water is). Some things thrive in water with a GH like ours, and some die. His other hobby is home brewing beer. Hardness can change the way enzymes react in the brewing process and impacts a bunch of other things that are lost on me and not terribly important to him. As with the aquarium, he can flush his mistakes into our septic system – but homebrew mistakes are first filtered through his kidneys. 

Strong bones and teeth. To be honest, I’ll take my mineral-infused beverages without the extra effort of fermentation or the addition of hops. Plain old hard water straight from the tap is what I prefer. And according to the World Health Organization (WHO), the addition of calcium and magnesium could be beneficial to health. What doesn’t kill us makes us stronger, right? It certainly seems to be true for my teeth, and I’m hoping also for my bones. I don’t care to test the hypothesis by falling on hard water converted to a solid state. But if or when I slip on the ice, I’ll let you know what I learn.

Donna Kallner writes from the white zone of rural northern Wisconsin, where a builder once advised her against glass shower doors and in favor of a shower curtain. When scummy with hard water and soap residue and company is coming, you can easily replace a curtain.

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