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How to Tell if You Have Hard Water?

For those of us living in an area with hard water, the effects of hard water can be seen all around us. Many people fail to notice the signs of hard water because they are unfamiliar with them. Nonetheless, the impact of hard water can be seen on faucets, fixtures, and surfaces around your house, as well as in your hair and on your skin. The impact of hard water can even be seen on the clothes you wear and the dishes you use.

If you have ever wondered how to know if you have a hard water problem, perhaps the easiest way is by looking for the most common signs of hard water around your home and on your body. There are also other methods, including having your water professionally tested or looking towards official sources for water quality in your area.

What is Hard Water?

The name sounds awfully contradicting, so what is hard water exactly? Water is referred to as “hard” when it is tested and found to have relatively high amounts of minerals. Most often, hard water contains high levels of calcium and magnesium. Hard water can also contain elevated levels of metal mineral buildup, such as iron, zinc, barium, manganese, and aluminum.

The opposite of hard water is referred to as “soft” water. Soft water has low amounts of minerals and can occur naturally, or as the result of a deionization  Many that have soft water in their home are usually using a home water softener system.

The Water Hardness Scale

Water hardness is a sliding scale, with soft water on one end of the spectrum and very hard water on the other end. A water hardness scale is a tool used to define exactly how hard water is. The unit of measurement used in the water hardness scale is grains per gallon (GPG), which is a measurement of the amount of dissolved calcium carbonate contained in a water sample. 

Here are how different levels of hardness are classified according to the most commonly used water hardness scale:

  • Water with less than 1 GPG of measured calcium carbonate is soft water.
  • Water measured to have between 1 – 7 GPG of calcium carbonate is moderately hard.
  • Water with anything between 7 – 10 GPG of dissolved calcium carbonate is hard.
  • Water with calcium carbonate levels of 10 GPG or above is considered very hard.

How Does Water Become Hard?

Water becomes hard through a natural process. Hard water isn’t like fluoride, which is added to water in most places throughout the United States to prevent tooth decay. Instead, the dissolved minerals that create hard water are accumulated as water slowly percolates through the ground.

Typically, surface water isn’t very hard. Groundwater, which is water that is found in the soil beneath the Earth’s surface, tends to be much harder because it is closer to the sources of minerals. 

Water is a powerful solvent, and as it moves through the ground it dissolves and picks up mineral ions. Once bound to water these mineral ions don’t become easily dislodged. Left untreated, the minerals will eventually be left behind as a deposit when water is heated or evaporated.

Strategies for Determining if You Have Hard Water

If you have ever wondered, “how do I know if I have hard water?”, there are some straightforward methods to easily tell if you have mineral buildup in your tap water. The easiest of these is to simply gain a better understanding of what the effects of hard water are, and look for those effects around your home. This is the most accessible method of determining if you have hard water and the easiest for any individual to do without additional tools or resources like a hard water test.

Before diving into the effects of a hard water problem, there are two other easy ways how to tell if you have hard water. The first is at-home testing, either by yourself using a kit or by a professional. The second is to get a copy of the most recent water quality report provided by your municipal water supply.

Here are the advantages and disadvantages of both methods:

  • At-Home Testing – Testing the water at your house has a number of advantages. It will tell you exactly how hard the water is in your house at the time of the test. This will give you the most accurate picture of your water hardness as possible. The hard water test is usually easy and straightforward, but it will require you to use a test kit that is either purchased or provided by your water supplier or a water purification company. An alternative option is to have your water professionally tested. Generally, water purification companies like Rayne can have a technician come out to your house and perform a water test, either for a nominal fee or free of charge.
  • Water Quality Report – One option is to take a look at the water quality report published by your water supplier. Municipal water suppliers test their water mineral content regularly. Water quality reports will usually contain a summary of the average of these tests, although some tests such as this one will measure hardness from a single sample. The advantage of this is that it is usually easily accessible on your water supplier’s website, and it provides you a great picture of not only how hard your local water supply is but what minerals and other substances it contains. The disadvantage of this is that it won’t provide you with a firm number for exactly how hard the water is in your house at any given time, and in some cases doesn’t provide information in a format that is easily understood or digestible.

So what is the best method for determining whether you have hard water? The answer depends on what you want. If you want to understand exactly how hard your water is, it is probably best to have it tested by a professional company. If you just want to understand whether you have hard water, then the best way is to gain a better understanding of the most common effects of hard water and look for those effects around your house and on your body.

Common Effects of Hard Water

If you have hard water in your house, you have most likely been battling the effects of hard water. When hard water comes into contact with a surface it leaves behind the dissolved minerals it carries in the form of an insoluble precipitate. While this may seem like a small thing, over time this precipitate causes the most frustrating effects of hard water.

Soap Scum

For people with hard water, battling soap scum just becomes a fact of life. Soap scum forms from a reaction between the minerals in hard water and the soap you use to clean or shower with. Soap scum is a whitish or yellowish film that builds up on surfaces that come into contact with both soap and hard water. Typically it will be found on faucets and in sinks, as well as in your bathroom shower and on your counters. 

Soap scum is difficult to clean and quick to build back up again after it has been removed. Although soap scum isn’t necessarily dangerous to the health, it is unsightly and can serve as a fertile breeding ground for mold. If you want to remove soap scum you’ll probably need to use an acid, such as vinegar.

Soap scum from suds doesn’t just form on the surfaces around your house. A film of soap will also be left behind on your skin when you use soap with hard water. Soap used in hard water doesn’t produce a good lather because lathering requires water to have free molecules. So most people end up using more soap or shampoo to compensate. This excess soap reacts with the minerals in hard water to leave a film behind.

Mineral Deposits

Mineral deposits are probably the easiest impact of hard water to recognize. In a household with hard water, mineral deposits are on everything that water touches. You’ll see these hard water stains on your faucets and bathroom fixtures, on your shower doors and bathtub, and in your sinks or on your dishes. When hard water evaporates or dries on a surface it leaves behind the dissolved minerals it was carrying as deposits. 

These mineral deposits often appear whitish in color due to the fact that they are usually calcium carbonate or magnesium. If your water is hard because of iron, these mineral deposits may appear red. 

The mineral deposits left behind by hard water can have a negative impact. These deposits form quickly when water is heated, which occurs in dishwashers, washers, water heaters, and coffee pots. These and other appliances that heat hard water can experience decreased operational efficiency over time. In a similar fashion, as water is piped throughout your house the minerals will slowly be deposited into the walls of the pipes, constricting the flow of water over time.

Though these hard water deposits are usually only a significant problem after they have happened for many years, it is worthwhile to be mindful of the ways hard water can impact the equipment and appliances throughout your house. More often, you’ll notice white dots on your pans and dishes, even after they are thoroughly cleaned. These don’t mean that your dishes are dirty, but rather are simply minerals left behind as hard water evaporated.

Skin Irritation

The skin irritation caused by hard water can be caused both by the film left behind when soap is used in hard water, as well as by the minerals contained in hard water itself. When you shower with hard water and dry off, tiny amounts of minerals are left behind as the water evaporates. These minerals can block pores and upset the delicate balance of healthy skin, leading to irritation.

The soapy film left behind on your skin after you shower or bathe with hard water can block pores. This film will also dry out skin, both by coating the skin and altering its PH as well as by serving as a barrier for helpful moisturizers and lotions. You’ll typically see skin irritation caused by hard water on individuals with sensitive skin, and on the most vulnerable part of their skin such as the scalp or face. You might also notice hard water effects on hair as well. Hard water can cause color to fade or dry out hair from root to tip.

Dingy, Faded Laundry

If the color of your clothes fades quickly, leading to dull and dingy looking clothing after only a few months, you most likely are washing your clothes with hard water in your washing machine. The minerals contained in hard water are deposited on the fibers of your clothing when you do your laundry. Over time, these minerals coat the fabric of your clothing and give it a dull appearance. This mineral coating will also rob the strength of the fibers of your clothing, leading your clothing to wear out more quickly than it would otherwise.

Closing Thoughts

The effects of hard water are so commonplace you might not have even realized what they were. Soap scum and mineral deposits can both be found in households that have hard water. Looking for these signs of hard water can let you know quickly and easily whether you have hard water in your house. Some of the other common effects of hard water include dry skin and faded and dingy laundry.

If you want to know exactly how hard the water is in your house, it is probably in your best interest to schedule an assessment with a water purification professional like Rayne. One of our experts can explain in-depth what a water softener does so you can decide if it’s the right solution for you. Not only are these tests free or low cost, but they can tell you exactly what the mineral content of the water in your house is.

To find out if you have hard water or to explore treatment options for your hard water like a home water softener system, please contact Rayne today.


  3. Ungvarsky, Janine. “Hard Water.” Salem Press Encyclopedia of Science, 2018.
  5. Luqman, Muhammad Waqas, Muhammad Haris Ramzan, Usama Javaid, Roshan Ali, Muhammad Shoaib, and Muhammad Ayyas Luqman. “To Evaluate and Compare Changes in Baseline Strength of Hairs after Treating Them with Deionized Water and Hard Water and Its Role in Hair Breakage.” International Journal of Trichology 10, no. 3 (May 2018): 113–17.