Understanding Hard Water: Benefits, Drawbacks, and Treatment Solutions

What is hard water and how does it impact your home and health? Defined by high levels of calcium and magnesium, hard water creates challenges such as limescale buildup and interferes with cleaning. Discover its effects, how to test for it, and ways to treat it in the following sections.

Key Takeaways

  • Water hardness is determined by the levels of calcium and magnesium in water, varying geologically and measured in units such as ppm, mg/L, or grains per gallon, with temporary and permanent hardness categories based on mineral composition.

  • Hard water causes practical problems such as appliance malfunction, limescale buildup, increased cleaning product use, and negative effects on cleaning effectiveness, while it can also provide essential minerals like calcium and magnesium beneficial for health.

  • Water hardness can be treated using various methods, including ion exchange softeners and reverse osmosis, with considerations towards alternative, eco-friendly solutions that reduce the environmental impact of traditional salt-based softeners.

Defining Water Hardness

Testing water hardness with DIY test kit

Hard water primarily contains high levels of calcium and magnesium. These minerals dissolve in the water as it moves through various geological formations. The quantity of these minerals in the water signifies its hardness. Therefore, discussing water hardness essentially refers to the measurement of dissolved calcium and magnesium in water.

The geological composition of a region largely determines the hardness of its water. Areas rich in limestone or chalk often have hard water, as these rocks are high in calcium and magnesium. When water falls as rain, it is naturally soft. However, as it flows through the ground and into our waterways, it picks up minerals like calcium and magnesium from the rocks and soil, which determine the hardness of the water in our taps.

Types of Hardness

Water hardness is classified into two types: temporary and permanent. Temporary hardness is due to the presence of bicarbonates of calcium, magnesium, or sodium dissolved in the water. This type of hardness can be reduced by boiling the water or adding lime, which increases the pH, causing the bicarbonates to precipitate out, leaving the water softer.

On the other hand, permanent hardness is mainly caused by sulfates and chlorides of calcium and magnesium, as well as calcium carbonate. These substances do not precipitate out when the water is boiled or when lime is added. Hence, addressing permanent hardness poses a challenge and demands advanced methods like ion exchange or reverse osmosis.

Measuring Water Hardness

Various units like dGH, °dH, ppm, mg/L, grains per gallon, °e, and °fH can measure water hardness. It’s like having different scales for measuring temperature: Fahrenheit, Celsius, and Kelvin. Each unit has its own range for classifying water as soft, moderately hard, hard, or very hard. For example, if we take the classification in mg/L, water is generally defined as:

  • Soft if it contains 0 to 60 mg/L of calcium and magnesium

  • Moderately hard if it contains 61 to 120 mg/L

  • Hard if it contains 121 to 180 mg/L

  • Very hard if it contains more than 180 mg/L.

The hardness of water can be assessed using multiple methods, ranging from simple DIY tests to precise test kits. A simple DIY test involves a clear bottle, pure liquid soap, and tap water. If the water doesn’t produce much foam or turns cloudy when shaken with the soap, it’s likely hard. For a more precise measurement of water hardness, you can use test kits with test strips and a color chart. These kits usually measure hardness in grains per gallon (gpg), with levels beyond 14 gpg considered ‘extremely hard’.

Impacts of Hard Water on Daily Life

Limescale buildup in a pipe

The high mineral content in hard water can pose several challenges in everyday life. These challenges include:

  • Maintaining household appliances and plumbing infrastructures

  • Increased use of cleaning products

  • Buildup of minerals in your kettle or coffee maker

  • Decreased performance of washing machine or dishwasher

These are all signs of hard water in your home.

Cleaning routines can also be impacted by hard water. The minerals in hard water react with soaps and detergents, reducing their effectiveness. This means you may need to use more laundry detergent or dish soap to get things clean. What’s more, hard water can leave behind a filmy residue on your:

  • dishes

  • glassware

  • skin

  • hair

This residue, often found in high concentrations, can be difficult to rinse off.

Soap Lathering and Mineral Stains

The minerals in hard water react with soap, forming a white precipitate, or soap scum, hindering the lathering process. As a result, you might need to use more soap or detergent for cleaning tasks and personal hygiene. Over time, this can lead to increased costs and waste, making hard water a less efficient option for households.

Moreover, the minerals in hard and soft water - particularly calcium and magnesium - can leave spots and limescale on surfaces such as faucets, glasses, and tiles. These mineral stains can be tough to clean and can leave your kitchen and bathroom looking less than sparkling. In contrast, soft water enhances the cleaning process, ensuring a richer lather with less soap and preventing mineral stain formation on washed items.

Plumbing and Appliance Damage

Significant damage to a home’s plumbing and appliances can be caused by hard water. As hard water flows through pipes and appliances, it leaves behind mineral deposits, or limescale, which can build up over time. This limescale can accumulate inside pipes and on appliances like showerheads and coffee makers, leading to reduced water pressure and impaired functionality. In severe cases, it can even cause pipes to become completely blocked.

Additionally, limescale buildup on appliance heating elements, such as those in kettles and water heaters, can impede efficient heat transfer, thus consuming more energy. Thus, not only does hard water lead to potential damage and costly repairs, it can also contribute to higher energy bills. This makes it crucial to address water hardness and consider suitable treatment options to prevent these problems.

Health Implications of Hard Water

Shower head with mineral deposits

While hard water can cause various challenges around the house, it’s not all bad news. Hard water is known to contain essential minerals such as calcium and magnesium, which can be an important dietary component. In fact, some studies suggest that magnesium intake from drinking hard water may protect against cerebrovascular disease, and women with higher intake of waterborne calcium showed a slight increase in femoral bone density.

However, there are also potential downsides to hard water when it comes to health. For instance, hard water has been linked to:

  • Dryness of the skin and hair

  • Negative effects on people with conditions such as eczema

  • Speculative relationship with health outcomes like cardiovascular health, with no definitive proof of adverse effects.

Calcium and Magnesium Intake

Essential minerals like calcium and magnesium, vital for various physiological functions, can be obtained from hard water. The calcium and magnesium concentrations in hard water contribute to the recommended daily allowance for magnesium, which is around 300-400 mg. Waterborne magnesium carbonates and magnesium salts can significantly help individuals with borderline magnesium deficiency meet their daily intake needs. So, while hard water may be a nuisance in terms of limescale and soap scum, it can contribute positively to your health by supplementing your intake of these essential minerals, including magnesium concentrations.

Additionally, cooking with magnesium-rich hard water can help mitigate the loss of magnesium from food. This provides an additional means of maintaining adequate magnesium levels in the body, further highlighting the potential health benefits of hard water.

Health Concerns and Debates

Despite potential health benefits of drinking hard water, it is worth noting the ongoing debates regarding its health implications. Some studies indicate potential protective roles of calcium and magnesium in drinking water against cardiovascular diseases. For example, certain regions showing reduced instances of such diseases are associated with higher water calcium content. However, hard water consumption has also been linked to an increased prevalence of atopic dermatitis due to mineral residues that are difficult to rinse off, contributing to dry, itchy skin and negatively impacting skin pH balance.

Moreover, ecological studies suggest an inverse correlation between water hardness and certain diseases, including cancer, with research finding significant protective effects of calcium and magnesium intake from drinking water on cancer risks. However, more research is needed to definitively prove these associations and fully understand the health implications of hard water.

Regional Variations in Water Hardness

Due to factors like geology, soil composition, and rainfall, water hardness can significantly vary from one region to another, affecting local water supplies. This means that the water in your home could be very different from the water in another part of the country, or even in a neighboring town.

For example, in Australia, following the Australian drinking water guidelines:

  • Melbourne’s water is very soft with around 10 ppm hardness

  • Adelaide’s water is quite hard at about 134-148 ppm

  • Sydney’s water ranges between 39.4 and 60.1 ppm

In the United Kingdom, water hardness varies significantly too. Very hard water often exceeds 200 ppm in areas east of the Severn and Tees estuaries, including London, while cities like Manchester and Birmingham have very soft water.

In Canada, water hardness exhibits extremes with the prairie provinces like Saskatchewan and Manitoba often exceeding 200 ppm, in contrast to Vancouver’s soft water with less than 3 ppm hardness, and Montreal sitting at a moderate level of 116 ppm.

Factors Influencing Regional Variations

Multiple factors influence the regional variations in water hardness. One of the primary factors is the geology of the area. Regions with geology that is susceptible to erosion and weathering, such as areas with limestone and chalk, are more likely to have hard water due to the release of calcium and magnesium into the water supply. Soils rich in nutrients or salts also contribute to regional variations in water hardness, particularly when those soils are part of a catchment that supplies a water body.

The hardness of water is also influenced by rainfall. Higher average rainfall intensities can lead to increased dissolution and transport of mineral constituents from soils into the water supply, influencing the hardness of regional water sources. Furthermore, land use and management practices, including vegetation cover and fertilizer application, can modify the quantity of minerals entering water bodies, thereby influencing regional variations in water hardness.

Examples from Around the World

Comprehending water hardness is not confined to local or regional concerns. It’s a global issue, with water hardness varying widely around the world. In the U.S., for example, the average water hardness is about 13 grains per gallon, which is classified as ‘very hard.’ Meanwhile, in Australia, water hardness varies significantly, with:

  • Melbourne having very soft water at around 10 ppm

  • Adelaide experiencing hard water levels of around 134-148 ppm

  • Sydney having moderate water hardness, with levels reported between 39.4 and 60.1 ppm.

In fact, these examples are just the tip of the iceberg. Comparing regions worldwide, there are definitive variances in water hardness, from the very soft waters in cities like Vancouver and Melbourne to very hard waters found in the prairie provinces of Canada and parts of the United Kingdom. This diversity in water hardness underscores the importance of understanding and managing water hardness, no matter where you are in the world.

Treatment Options for Hard Water

Water softening system with ion exchange

Considering the potential downsides of hard water, you may ponder over the treatment options. Thankfully, there are several ways to treat hard water, helping to prevent the associated issues and improve water quality. These treatment methods include both water softening systems and alternative solutions, each with its own strengths and weaknesses depending on your specific needs and circumstances.

Water softening systems are a common treatment method. These systems work by reducing the mineral content in hard water, making it softer and less likely to cause limescale build-up and other issues. Another option is to use water filters, which can remove some of the minerals from the water. However, it’s important to note that after using water filters, the water still contains:

  • fluoride

  • calcium

  • magnesium

  • sodium

Water Softening Systems

Various types of water softening systems exist, each reducing water hardness in its unique way. The most common type is a salt-based ion exchange softener. These systems work by running hard water through a resin coated with sodium ions. As the water passes through the resin, the hard water ions (calcium and magnesium) are exchanged for sodium ions, resulting in softer water.

Other types of water softeners include:

  • Salt-free systems, which utilize template-assisted crystallization (TAC) to neutralize minerals

  • Dual-tank softeners

  • Magnetic softeners, which modify the structural formation of minerals to prevent scaling

  • Reverse osmosis softeners

  • Shower head softeners

These alternatives to conventional salt-based softening methods can be particularly useful for those looking to avoid the environmental impact of salt discharge or the maintenance requirements of traditional systems.

Alternative Solutions

Besides water softening systems, multiple alternative solutions can treat hard water. One of these is the use of water filters. These devices can be installed at specific faucets (point of use) or for the entire home (point of entry) and are designed to address hard water problems. While they may not reduce the overall hardness of the water, they can help to remove some of the minerals that contribute to the hardness.

Another alternative is the use of descaling agents. These products work by removing built-up minerals in plumbing systems and appliances. While they do not alter the overall hardness of the water, they can help to prevent the negative effects of hard water, such as limescale build-up and reduced appliance efficiency.

Environmental Considerations

Environmental impact of salt discharge

While treating water hardness can significantly enhance the functionality of home appliances and potentially benefit health, the environmental implications of such treatment must be considered. Traditional water softeners often use ion exchange techniques that require salt, which can lead to increased sodium in discharged water. This increased salt can be harmful to aquatic life and may disrupt local ecosystems.

Additionally, salt-based water softening can lead to soil salinization, impacting soil health and agricultural productivity. The extraction and processing of salts for water softening also contribute to environmental degradation and resource depletion. Therefore, while treating hard water can have many benefits, it’s crucial to consider the environmental impact and look for more sustainable options.

Wastewater and Salt Discharge

Water softening can have negative environmental impacts, including:

  • Elevating wastewater salinity, which can harm aquatic life when discharged into water bodies

  • Improper disposal of waste salt or potassium chloride from water softener regeneration, which can contaminate soil and groundwater

  • Harm to local ecosystems and potential risks to human health if contaminated water is used for drinking or irrigation.

Furthermore, water softeners can contribute to increased greenhouse gas emissions due to energy consumption during the regeneration process. The high volume of wastewater generated from water softening processes and other uses also poses a challenge for sustainable water management and conservation efforts. Therefore, when considering water softening options, it’s important to consider the environmental impact and look for solutions that minimize wastewater and salt discharge.

Environmentally Friendly Alternatives

Due to environmental concerns related to traditional water softeners, interest in eco-friendly alternatives has been increasing. Such alternatives encompass salt-free systems, magnetic water treatment devices, and reverse osmosis systems. Among these alternatives, hot water systems that use template-assisted crystallization (TAC) as salt-free water softeners change the properties of water to prevent scale without adding sodium. This makes them an environmentally friendly solution, particularly in areas where traditional softening methods are restricted.

Magnetic water treatment devices use magnets to change the physical behavior of minerals in hard water, preventing them from sticking to surfaces. They operate without the need for electricity or salt, making them a great eco-friendly option. Similarly, reverse osmosis systems not only provide high-quality drinking water but also mitigate chemical and salt use by effectively removing a broad spectrum of contaminants, including hard water minerals. These systems offer low-maintenance and environmentally conscious options, emphasizing the importance of sustainable solutions in hard water treatment.


In conclusion, understanding water hardness is crucial given its wide-ranging impacts on our daily lives and the environment. From limescale buildup in appliances and plumbing systems to the potential health implications, hard water poses several challenges. However, with the various treatment options available, from traditional water softening systems to environmentally friendly alternatives, we can effectively manage and mitigate these challenges. As we journey towards a future of sustainable living, let’s remember that every drop counts, and the softest water can make the biggest waves.

Frequently Asked Questions

How do you remove hardness from water?

The most effective method to remove hardness from water is by using a water softener that uses a salt solution and resins. This will prevent scale buildup and provide cost-effective results. Other effective methods include reverse osmosis, lime-soda method, distillation, chelation, and ion exchange.

Is it good to drink hard water?

Drinking hard water is not considered a health hazard and can contribute a small amount of calcium and magnesium to your diet, according to the National Research Council and WHO.

How do you know if water is hard?

You can tell if water is hard by looking for stains on surfaces, deposits on faucets, and difficult-to-remove soap scum or residue. These are common symptoms of hard water.

Is Australian water hard or soft?

Australian water can range from soft to hard depending on the state, with Victoria and Tasmania having the softest water and Western Australia and South Australia having some of the hardest. Soft water is preferred by those with eczema and psoriasis and results in silkier hair and skin.

What is hard water?

Hard water is water with a high mineral content, mainly calcium and magnesium, due to the dissolution of minerals as it passes through geological formations of the Earth.