PH Of Hard Water: What You Need To Know

Table of Contents

The Importance of pH in Water

Have you ever wondered why some water tastes different than others? Or why your appliances and water lines seem to wear out faster than they should? The answer may lie in the pH level of your water. Many homeowners are unaware that the presence of alkaline compounds in their water can affect its taste and quality, causing damage to devices over time. Adding a small amount of lemon juice can help balance the pH level and improve the overall quality of your water.

pH levels determine the acidity or alkalinity of water, with 7 being neutral on the pH scale ranging from 0 to 14. Low pH levels can cause corrosion in pipes and lead to lead contamination in water. On the other hand, high pH levels can cause mineral buildup and reduce the effectiveness of chlorine disinfection. Alkaline compounds can increase the pH level of water, which is measured in ppm (parts per million) to determine the number of calcium ions present.

It’s important to note that different terms are used depending on the concentration of hydrogen ions in a sample of water, which can be estimated using a device that measures the pH value.

 For example, parts per million (ppm) is used for low concentrations while molarity is used for higher concentrations. Additionally, alkaline compounds can affect the pH value of water and require special attention in water treatment processes.

Which contains high concentrations of minerals such as calcium and magnesium compounds, understanding the pH value and ppm is crucial to estimate its quality. Hard water with a high hydrogen ion concentration has a low pH value, which can affect not only its taste but also its performance in household appliances.

PH of Hard Water

PH of Hard Water

Understanding Water Hardness and Its Relationship with pH

What is Water Hardness?

Water hardness refers to the amount of dissolved compounds and metals in a water sample, including high concentrations of calcium and magnesium ions. These minerals can cause scaling and buildup in plumbing systems and appliances due to their pH value. The level of water hardness is measured in parts per million (ppm) or grains per gallon (gpg).

How is Water Hardness Determined?

Water hardness can be determined through a simple test that measures the concentration of calcium and magnesium ions in the water sample, as well as its ph value and compounds. This test can be performed at home using a water testing kit or by sending a sample to a laboratory for analysis. The results are usually expressed in parts per million (ppm).

How Does Water Hardness Affect pH?

The pH of hard water can range from slightly acidic to slightly alkaline depending on the mineral content. When there is a high concentration of calcium and magnesium ions in the water, they release hydrogen ions (H+) into the solution, making it more acidic. However, these same minerals also have an alkalizing effect on water because they bind with hydroxide ions (OH-) to form insoluble salts.

How Does pH Determine if My Water is Hard or Soft?

While pH alone cannot determine whether water is hard or soft, it can provide some indication based on its range. Generally, soft water has a pH between 7-8 while hard water has a pH above 8.5 due to its high mineral content.

Using a Chart to Determine Water Hardness

A chart called the Langelier Saturation Index (LSI) can be used to determine the hardness level of water based on its pH and mineral content, including high concentrations. The LSI takes into account factors such as temperature, total dissolved solids, and alkalinity levels to calculate whether the water is corrosive or scaling.

The LSI chart ranges from -3 to +3 with 0 being neutral. If your LSI score falls below -0.5 and the pH value is low, the water is considered highly corrosive and can damage plumbing systems and appliances. If it falls above +0.5 and the pH value is high, the water is considered scaling and can cause buildup.

Importance of Understanding Water Hardness and pH

Understanding the relationship between water hardness and pH is crucial for maintaining plumbing systems and appliances. Hard water can cause scaling, which can lead to reduced efficiency, increased energy consumption, and premature equipment failure. Hard water can affect the taste of food and beverages made with it.

By monitoring your water hardness levels and pH, you can take steps to prevent damage to your plumbing systems and appliances. This may include installing a water softener or using a descaling agent to remove buildup.

Determining if Hard Water is Acidic or Not

If you’re living in an area with hard water, you may have concerns about the pH level of your water. Hard water contains high levels of calcium ions, which can affect the acidity or alkalinity of your water.

What is Hard Water?

Hard water is a type of water that has high mineral content, specifically calcium and magnesium ions. These minerals are picked up as the water flows through rocks and soil before reaching your home. The pH value of hard water can also be affected by these minerals. While hard water isn’t necessarily harmful to your health, it can cause issues with plumbing and appliances over time.

Is Hard Water Acidic or Basic?

Hard water isn’t typically acidic or basic; instead, it tends to be neutral. This means that its pH level falls around 7 on the pH scale. However, some types of hard water may be slightly alkaline due to their higher mineral content.

Testing the Acidity or Alkalinity of Hard Water

Testing the acidity or alkalinity of hard water can be done using litmus paper. Litmus paper changes color depending on whether a solution is acidic (pH below 7), neutral (pH 7), or basic (pH above 7). To test your hard water:

  1. Obtain a sample of your tap water.
  2. Dip a piece of litmus paper into the sample.
  3. Observe the color change on the paper.
  4. Compare the color change to a pH chart to determine whether your hard water is acidic, neutral, or basic.

Why is Hard Water Not Acidic?

Hard water isn’t typically acidic because calcium carbonate, one of its main components, acts as a buffer against acids in the environment. When exposed to an acid source such as carbon dioxide in air pollution or acid rain, the calcium carbonate in hard water reacts with the acid to neutralize it. This reaction results in a less acidic environment and helps to maintain a neutral pH level.

Acidic Water and its Effects

While hard water isn’t typically acidic, some types of water can be. Acidic water has a pH level below 7 and can cause damage to plumbing and appliances over time. The acidity in the water can corrode metal pipes, leading to leaks or even burst pipes. It can also cause damage to appliances such as dishwashers and washing machines, reducing their lifespan.

Importance of Determining Acidity of Hard Water

Determining the ph value of your hard water is important for choosing the appropriate treatment method. If your hard water is slightly alkaline, you may not need any treatment at all based on its ph value. However, if it’s acidic or highly alkaline according to its ph value, you’ll need to consider treatment options such as a water softener or an acid neutralizer system.

Ideal pH level for drinking water in a home setting

The pH level is an important factor to consider. The ideal pH level for drinking water in a home setting is neutral, which is around 7.0 on the pH scale.

What should be the pH of drinking water?

The ideal pH level for drinking water is between 6.5 and 8.5, with a neutral pH of 7 being optimal. Municipal water suppliers are required to maintain a safe pH level for drinking water, but home water sources may vary in pH level due to ion concentration levels.

Why is it important to monitor and adjust the pH level of home drinking water?

Drinking water with a high or low pH can potentially cause health problems. Water with a low pH (acidic) can leach harmful metals such as lead from pipes into your drinking water, while high-pH (alkaline) water can cause gastrointestinal issues and skin irritation.

How can you test the ph of your drinking water?

There are various ways to test the pH of your home’s tap or well water:

  • Use a digital or litmus paper test kit to check the quality of your home water. These kits are readily available at hardware stores and online retailers and can help you determine if your water sample is affected by acidic water or if you need to use a water conditioner.
  • Send samples to a lab: Many local labs offer testing services that provide more detailed information about your home’s tap or well water.
  • Purchase an electronic tester: These devices measure both alkalinity and acidity levels of water samples, including acidic water and hard water pH. It is recommended to use a water conditioner before taking the water sample for accurate readings.

How can you adjust the ph of your home’s tap or well water?

If you find that your home’s tap or well water has an undesirable PH value below 6.5 or above 8.5, there are several methods for adjusting its PH value:

  • Acid injection: This method involves injecting acid into your home’s water supply to lower the pH level.
  • Neutralization: This method involves adding a water conditioner, such as lime or soda ash, to a water sample to increase the pH level.
  • Aeration: This method involves exposing your home’s water supply to air, which increases its oxygen levels and lowers its pH value.

What should be the pH of soft drinking water?

Soft drinking water is typically slightly acidic, with a pH range of 6.5 to 7.5. This range is safe for consumption and does not pose any significant health risks.

Treating pH levels in hard water vs soft water

There is a significant difference between hard and soft water. Soft water has a naturally lower pH level than hard water, which means that treating its pH levels is less necessary than in hard water.

What is the pH of hard and soft water?

The pH level of any water sample determines whether it is acidic or alkaline (basic). The scale ranges from 0 to 14, with 7 being neutral. A value below 7 indicates acidity, while above 7 indicates alkalinity.

The natural pH of soft water ranges from about 6.5 to 8.5, depending on the source and treatment process. On the other hand, hard water typically has a higher pH range of around 7.5 to 10.

Why treat the pH levels in hard and soft water?

Treating the pH levels in both types of water can help prevent corrosion and scaling issues in pipes, appliances, and fixtures that come into contact with the water.

In hard water areas where high mineral content causes scaling issues such as limescale buildup on faucets, showerheads, or even inside pipes over time, an acidic treatment can reduce the hardness level by dissolving some minerals like calcium carbonate.

Softened Water systems are designed to remove excess minerals from your home’s tap supply using ion exchange resin technology. This system exchanges calcium and magnesium ions for sodium ions through a process called ion exchange before delivering treated softened drinking and washing waters throughout your home.

How to treat the pH levels in hard and soft waters?

Hard Water

  1. Acidic Treatment: Adding an acidic solution such as vinegar or citric acid can help reduce the hardness level of water by dissolving some minerals like calcium carbonate and adjusting the water’s pH.
  2. Reverse Osmosis: This filtration system uses pressure to force contaminated liquid through a membrane that removes impurities, including minerals that cause hardness. It also helps regulate water pH levels.
  3. Water Softener: This treatment system uses ion exchange resin technology to remove excess minerals from the water, replacing them with sodium ions.

Soft Water

  1. Acidic Treatment: While soft water has a naturally lower pH level than hard water, acidic solutions can still be used to reduce alkalinity levels if necessary.
  2. Alkaline Treatment: Adding an alkaline solution such as baking soda or potassium hydroxide can help raise the pH level of soft water if it is too low.
  3. Neutralization: If the pH level is too high or low, adding a neutralizing agent like sodium carbonate can balance out the acidity or alkalinity levels.

Impact of using hard alkaline water in everyday household use

Many homeowners unknowingly use hard alkaline water for their household chores.

Hard water is a common problem in many households, and most homeowners are unaware of its effects. Hard water is characterized by high levels of dissolved minerals such as calcium and magnesium. While these minerals are not harmful to human health, they can have a significant impact on the quality of life at home

Some of the most significant impacts of using hard alkaline water are:-

  • Alkaline compounds in hard water can damage appliances and reduce their lifespan.
  • Using hard alkaline water can also cause skin irritation and dryness.

Alkaline compounds in hard water can damage appliances and reduce their lifespan.

The presence of alkaline compounds in hard water can also cause damage to appliances such as washing machines, dishwashers, and coffee makers. These compounds react with metal surfaces inside these appliances, leading to corrosion and rusting over time. As a result, the lifespan of these appliances is reduced significantly.

Furthermore, when hard alkaline water is heated, it forms limescale deposits that can clog pipes and reduce the efficiency of hot water systems. This leads to higher energy bills since more energy is required to heat up the same amount of water due to reduced efficiency.

Using hard alkaline water can also cause skin irritation and dryness.

Another impact of using hard alkaline water is that it can cause skin irritation and dryness. The high level of minerals present in this type of water makes it difficult for soap or body washes to lather effectively. This leaves a residue on your skin which causes dryness and itching.

Moreover, when you take a shower with hard alkaline water, your hair may feel rougher than usual due to mineral buildup on the scalp. This could lead to hair breakage and split ends, causing further damage.

Will a water softener change the water’s pH?

If you’re dealing with hard water, you may be wondering if a water softener can help improve your water’s pH level. Hard water is caused by minerals such as calcium and magnesium in the water supply. These minerals can cause issues such as scale buildup, reduced soap effectiveness, and other problems. But does hard water also have high pH levels? And will a water softener change the pH of your water?

Does hard water have high pH?

Hard water does not necessarily have high pH levels. The hardness of the water refers to the amount of dissolved minerals in it, while pH is a measure of how acidic or alkaline the water is on a scale from 0 to 14. Neutral pH is 7; below 7 is acidic, and above 7 is alkaline. While some sources suggest that hard water tends to be slightly alkaline due to its mineral content, this isn’t always true.

How do you test your water’s pH level?

To test your tap or well-water for its pH level, you can use a simple home testing kit available at most hardware stores or online retailers. These kits usually come with litmus paper strips that change color when exposed to different levels of acidity or alkalinity. You simply dip one end of the strip into your sample of tap or well water for several seconds, then compare it against a chart included with the kit to determine its approximate pH level.

Can a Water Softener Change Water’s PH Level?

The process of removing hardness from your tap or well water using a salt-based ion exchange system does not affect its overall acidity or alkalinity (pH). A typical residential-sized ion exchange unit consists of two tanks: one filled with resin beads that attract and remove dissolved calcium and magnesium ions from incoming hard water, and another tank filled with salt or potassium chloride that regenerates the resin beads by flushing them with brine. This process does not alter the pH level of the water.

What can affect water pH levels?

While a water softener doesn’t change your water’s pH level, there are other factors that can influence it. These include:

  • Chemicals: Chlorine, fluoride, and other chemicals added to public water supplies can affect its pH level.
  • Pollution: Industrial runoff or agricultural waste can cause contamination of groundwater sources, leading to changes in pH levels.
  • Natural geological features: Certain types of rock formations contain minerals that can leach into groundwater sources and change their pH levels.

Importance of maintaining the right pH balance in the water

Maintaining the proper pH balance in the water is crucial for ensuring its quality and safety. Water hardness and pH are closely related, and determining whether hard water is acidic or not is important in establishing the ideal pH level for drinking water in a home setting. It’s also essential to understand how to treat pH levels in both hard and soft water.

Using hard alkaline water in everyday household use can have negative effects on your health, including skin irritation, dryness, and even hair loss. A water softener can help alleviate some of these issues by removing minerals that cause hardness from the water. However, it’s important to note that a water softener may not necessarily change the pH level of your water.


Q: Can high-pH levels affect my plumbing system?

A: Yes! High pH levels can cause corrosion of pipes over time, leading to damage that may require costly repairs.

Q: What happens if I drink hard alkaline water?

A: Drinking hard alkaline water regularly can lead to health complications such as gastrointestinal problems, skin irritation, dryness, and hair loss.

Q: How do I know if my tap water has a high or low pH level?

A: You can purchase a simple testing kit online or at your local hardware store to test your tap water’s current pH level.

Q: Is it safe to drink slightly acidic tap water?

A: Slightly acidic tap water is generally safe for consumption but may taste unpleasant due to its sour flavor profile.

Q: Can I use a water softener to change the pH level of my water?

A: While a water softener can help remove minerals that cause hardness, it may not necessarily change the pH level of your water. Consider investing in other treatment options if you need to adjust your home’s pH balance.


In conclusion, maintaining the right pH balance in your household’s drinking water is crucial for ensuring its safety and quality. Treating hard or soft water to achieve an ideal pH level can help reduce negative health impacts associated with using hard alkaline water. Consider investing in a reliable testing kit to determine your home’s current pH level and take necessary measures accordingly.

About the author

I am Leena Raswant, a chemistry postgraduate. I thrive on challenges and continually specified goals. I aim to learn, unlearn, relearn and spread my knowledge in the best possible ways.