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The Difference Between Hard & Soft Water

*Reviewed by Ken Christopher, Senior Vice President at Rayne Dealership Corporation

If you have ever wondered, “what is the difference between soft and hard water?” then you aren’t alone. You’ve probably heard stories about how certain locations have hard water, while others have soft. Or you may have heard about a home water filtration system, but don’t know what it is. You may have even looked into whether the water being piped into your house is hard.

Water hardness is a relatively simple concept that can have quite a large impact. This impact isn’t always easy to discern, particularly if you have always experienced the same type of water your whole life.

In this article, we’ll work to break down the difference between hard and soft water. We’ll take a look at what hard water is, what properties make it that way, and explore what the impact of hard water is. While there are downsides to hard water, you may have been dealing with the impact of hard water your whole life and never realized it. By shedding light on what makes water soft or hard and the real impact of hard water, you can make an informed decision about whether a home water softener system is right for you and your family.

What is Water Hardness?

It seems odd to talk about a liquid in terms of whether it is hard or soft. The reasoning behind the nomenclature of these terms is not readily apparent from the outside, which has led to a great deal of confusion over the years.

Put simply, water hardness is related to minerals in your water. Specifically, water hardness comes down to the content of calcium and magnesium that is in your water. Water that is considered “hard” has higher amounts of these minerals in it than water that is considered “soft”.

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How is Water Hardness Measured?

Now that we know water hardness is determined by the mineral content, let’s take a look at the thresholds between hard water vs soft water. There are actually four ranges of hardness in water; soft, moderately hard, hard, and very hard which can be measured on the water hardness scale.

Here are the thresholds for the hardness of water, broken down by the number of Grains Per Gallon found in the water:

  • <1 GPG of hardness is considered soft water.
  • 1-7 GPG of hardness is considered moderately hard.
  • 7-10 GPG of hardness is considered hard.
  • Anything over 10 GPG is considered very hard.

How Does Water Hardness Occur?

We measure water hardness by determining the concentration of calcium carbonate that is found in the water. Calcium carbonate is so abundant that you have probably interacted with it on a daily basis throughout your life, whether you have realized it or not. The most recognizable form of calcium carbonate to us is probably chalk, such as the type used in schools. Calcium carbonate comprises roughly 4% of the Earth’s crust and is found in paint, plastics, building materials like shingles and mortar, as well as baking powder, toothpaste, and even wine.

Alongside calcium, magnesium levels are also higher in hard water. Iron and other metals may be present in higher concentrations as well. The high mineral content that characterizes hard water is incorporated as the water moves throughout the Earth’s crust. As it seeps through the chalk and magnesium in the soil on its way to the natural reservoirs that make up our groundwater supply, water dissolves calcium, magnesium, and other dissolved minerals.

Due to the fact that water hardness is caused by the passage of water through soil that is rich in minerals, it should come as no surprise that there is a strong geographic correlation to the hardness of the water. Different areas will have varying concentrations of magnesium, calcium, and other dissolved minerals that are higher or lower than others. The higher the concentration of minerals in the soil around the groundwater source, the harder the water from that source will be.

An image provided by the U.S. Geological Survey’s 1975 National Water-Quality Assessment (NAWQA), found here, demonstrates the strong regional variation in water hardness that can be found throughout the United States. A brief glance at the image shows that water tends to be harder in the central and southwestern United States while being predominantly softer along the east coast of the United States and the northwestern United States.

It should be noted that this image simply shows regional trends, but does not account for the actual water hardness you might have at the tap. In order for that to be accurately determined, you would have to test the hardness of your water. Still, the image is useful for reinforcing the fact that a key factor between hard vs. soft water is the mineral content in the soil that our groundwater passes through.

What is the Impact of Water Hardness?

You may be scratching your head at this point, wondering what the big deal is. Well, even if water hardness isn’t as detrimental as some might have you believe, there are some very real negative impacts associated with hard water.

Understanding the real-world impact of water hardness goes a long way toward answering the question, “what is the difference between hard and soft water?” It can also help you better understand what is a water softener and the impact it could have. Some of the effects of hard water you may already be familiar with, while others you may not ever experience.

Drawbacks of Hard Water

Since most people are concerned about the impact of hard water on their drinking water, let’s examine some of the drawbacks of hard water quality.

Mineral Buildup

Mineral buildup is probably the biggest drawback of hard water. As the term suggests, mineral buildup is the accumulation of minerals carried in the water on surfaces the water moves through or touches. Common areas where you will see limescale buildup are in pipes, on equipment, chrome, tile, fiberglass, and glass. If you live in an area with hard water, you’ve probably seen the buildup of minerals on your sink faucets and other plumbing fixtures. If the fixture is older, these mineral deposits will be readily apparent. This limescale buildup can also affect water flow in households as well.

The color of the buildup you experience from your tap water will change depending on the concentration of minerals in your water supply. Limescale, the term used for the buildup of calcium carbonate and magnesium, appears off-white or chalky. A buildup of manganese may look brown or black. Water that contains high concentrations of iron will produce stains that look reddish. These hard water minerals can cause damage in some cases.

Mineral buildup from hard tap water can be a problem that is both tedious and unsightly for the average homeowner, and costly damage can occur as well. Water heaters are key areas where buildup occurs, as the water evaporating leads to the rapid accumulation of calcium carbonate. The pipes running through your house will also develop mineral buildup over time, slowly reducing the amount of water that can flow through your pipes as limescale buildup narrows the width of the pipe.

Mineral buildup on plumbing fixtures, glass shower doors, and showerheads, as well as the low water pressure can also be extremely common. This buildup can result in damage that requires replacement once the mineral buildup penetrates the coating on these fixtures. Also keep in mind that all appliances that have water flowing through them, such as your coffee pot, washing machine, and dishwasher will eventually experience mineral buildup that may impact their performance over the long term. Specifically, mineral buildup around the seals or valves in this equipment can result in water leaks.

While the mineral buildup from hard water in your home appliances and piping can be detrimental over the long term and may require more frequent cleaning or replacement of certain equipment, water hardness can be particularly damaging in industrial applications. Industrial equipment such as boilers and heaters are very susceptible to the ravages of mineral buildup. Because of this, many industrial users choose to implement water softeners to avoid any equipment damage stemming from water hardness in their local water supply.

Soap Scum

Soap scum is an unsightly and frustrating effect of water hardness. Soap scum is the result of a reaction between the calcium in hard water and the soap you use every day. The result is a solid substance that coats surfaces throughout your house, but particularly in your bathtub, shower, sinks, and anywhere where tap water and soap are used.

Soap scum is very unsightly and can be difficult to remove if it is allowed to build up. Eventually, soap scum can combine with mildew or mold, both of which are common in damp areas where soap scum is likely to form.

Spotted Dishes

Another hard water problem that may be common is spotted dishes. Ever wonder why you can’t seem to get your dishes clean, no matter how much you hand wash them or run them through the dishwasher? If your dishes come out of the dishwasher with white water spots on them, don’t run out and buy a new dishwasher. The cause is from cleaning with hard water. Streaks and spots on dishes are common negative outcomes associated with hard water.

Dull Hair

Just like how hard water makes cleaning the surfaces in your house difficult, your water may also be having an impact on how your hair looks and feels. Hard water will impact hair by making it dull in appearance and rough to the touch. It also becomes more difficult to rinse out all of the soap that you use, which makes that soap less effective at washing your hair. The next time you notice dull hair or difficulty rinsing out soap, it may be a hard water problem and it may also be time for a water softening system.

Closing Thoughts

Water hardness refers simply to the level of minerals that are found in a sample of water. The initial, natural state of water – such as rainwater – doesn’t have these hard properties, rather, it occurs once water enters and passes through the soil and stone. That being said, there is a strong geographical correlation between water hardness and location. Water will naturally be harder when the soil around the source of groundwater contains higher levels of calcium and magnesium.

Water that contains more minerals can have detrimental effects found throughout your home and impact your overall water quality. You may notice a buildup of minerals on faucets, showerheads, and plumbing fixtures. Minerals in hard water will also build up in appliances like your dishwasher and water heater, eventually affecting the efficiency of this equipment. Hard water, when combined with common soap, forms soap scum which is unsightly and difficult to clean. Additionally, with hard water, your clothes can become less resilient and your hair becomes harder to clean.

Thankfully, there are effective water softening solutions on the market if you are tired of dealing with the impact of hard water. In fact, there are water filter systems that can help you bring purified water right into your home. Don’t know how a water softener works? To learn more about water softening solutions or a home water filtration system, please contact Rayne Water today!

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Expert Reviewer – Ken Christopher