How to Filter Hard Water: 6 Common Solutions

Updated on:
October 23, 2023

You’ve probably heard of hard water, maybe even experienced it. The odds are you have — it’s estimated that around 85% of US homes have hard water.

This can have annoying and costly effects on your appliances, from your hot water heater to your washing machine, as well as your plumbing system, and even your hair and clothes. 

In this comprehensive guide, we’ll explore how you can remove or neutralize those hardness-causing minerals for soft water and a healthier, happier home.

Solutions for Hard Water

1. Whole-house water filtration system

A whole-house reverse osmosis (RO) water filtration system, also known as a point-of-entry system, is a comprehensive solution for dealing with hard water. This system is installed at the point where the water supply enters your home, ensuring that all the water used in your home — whether it’s for showering, cooking, laundry, or drinking — is treated.

These systems work by filtering out hard water minerals like calcium and magnesium, along with other potential impurities. 

Reverse osmosis systems use a semipermeable membrane to remove a wide range of impurities, including hard minerals, from the water.


  • Comprehensive solution to treat all the water in your home
  • Protection of appliances and plumbing
  • Safe drinking water
  • Softened water


  • Initial cost
  • Maintenance
  • Wasted water

2. Salt-based water softener systems

The most effective water softeners work on a principle known as ion exchange, replacing the calcium and magnesium ions that make water hard with softer potassium or sodium ions. However, newer technology attempts to soften water without ion exchange, leading to several types of water softeners.

Ion exchange softeners typically consist of a mineral tank filled with small resin beads that carry a negative charge. The positive calcium and magnesium ions are attracted to the resin beads as hard water flows through the mineral tank, effectively removing them from the water. In their place, sodium or potassium ions are released into the water, making it soft.

These are the most common types of water softeners. They use the ion exchange process to replace hard water ions with sodium or potassium ions


  • Highly effective at removing hard minerals from water
  • Improved water quality
  • Extended home appliances lifespan


  • Sodium addition a concern for some people
  • Costly and time-consuming maintenance
  • High water and salt usage in some cases

3. Salt-free water conditioners

Unlike water softeners that remove the minerals causing hardness, water conditioners simply change the structure of these minerals, particularly calcium and magnesium, to prevent them from depositing as scale. They use various technologies to alter the physical characteristics of the minerals in hard water:

  • Magnetic or electronic water conditioners: These devices produce an electromagnetic field that changes the electromagnetic properties of the calcium carbonate minerals, causing them to repel each other and prevent scale.
  • Catalytic media conditioners: These use a physical media that causes the calcium and magnesium to crystallize or change their form so they can’t stick to surfaces.
  • Template-assisted crystallization (TAC) or nucleation assisted crystallization (NAC): These advanced technologies convert the calcium and magnesium minerals into harmless crystal particles that flow freely with the water and don’t form scale.


  • No salt or chemicals
  • Maintenance-free
  • Preserves beneficial minerals


  • Doesn’t actually soften water
  • Questionable effectiveness

4. Distillers

Water distillers are a type of water purification system that can effectively remove many contaminants, including the minerals that cause water hardness. They work by mimicking the natural process of evaporation and condensation, which is one of the most effective ways to purify water.


  • Highly effective at removing a wide range of contaminants.
  • Produces extremely pure water
  • Low maintenance


  • High energy use
  • Impractically low speed and output
  • Removal of beneficial minerals

5. Washing soda

Washing soda, also known as sodium carbonate, is a powerful and natural alkaline substance that can neutralize acidic minerals like calcium and magnesium, making it easier for soap to lather and effectively clean.

It works by precipitating the calcium and magnesium ions in hard water. This means it turns these ions into a solid substance that can be easily removed. When you add washing soda to hard water, it reacts with the ions, forming a precipitate that can be easily washed away.

Adding a small amount of washing soda to your washing machine can help to soften the water, allowing your detergent to work more effectively. This can result in cleaner, fresher clothes.

Washing soda can also be used to treat hard water in other areas of your home. For example, you can add it to your dishwasher to help prevent mineral buildup, or you can use it to clean hard water stains from your bathroom fixtures.


  • Natural and eco-friendly
  • Effective
  • Versatile


  • Temporary solution
  • Doesn’t remove other impurities
  • Requires handling precautions to avoid skin irritation or eye damage

6. Chelation

Chelation involves the use of chelating agents, which are substances that can bind to the hard minerals in water, forming a complex that can be easily removed.

These work by forming multiple bonds with a single metal ion, in this case, the magnesium and calcium ions in hard water. This forms a ring-like structure, known as a chelate, which is stable and can be easily removed from the water.

The most commonly used chelating agent for hard water treatment is EDTA (ethylenediaminetetraacetic acid). EDTA is a hexadentate ligand, which means it can form six bonds with a metal ion, creating a very stable complex. When EDTA is added to hard water, it binds to the magnesium and calcium ions, effectively removing them from the water.

You can add a chelating agent to your laundry to help soften the water and make your detergent more effective. Some dishwashing detergents also contain chemical agents to help prevent mineral buildup on your dishes.

In addition, there are chelating shampoos and other care products available that can help to remove hard water buildup from your hair. 


  • Highly effective at treating hard water
  • Versatile
  • Environmentally friendly


  • Doesn’t remove other contaminants
  • Expensive
  • May require professional installation

Do You Have Hard Water?

Hard water is common, sure, but just because you’re having issues doesn’t mean it’s hard water. It could be something else within your plumbing system. So before you invest in a water softener, it’s a good idea to test your water for hardness. 

DIY testing for hard water

If you’ve noticed signs of hard water in your home, such as soap not lathering well, spots on dishes, or hard water scale buildup on faucets, you might want to conduct a simple DIY test:

  1. Take a clear, clean bottle with a cap. A water bottle or a clear jar would work perfectly.
  2. Fill about one-third of the bottle with tap water from your home.
  3. Add a few drops of pure liquid soap. Avoid using detergent or dish soap because they contain ingredients that are designed to lather even in hard water.
  4. Put the cap on tightly and shake the bottle vigorously for a few seconds.
  5. Observe the water. If the water has a lot of bubbles and appears clear, then you likely have soft water. However, if the water looks milky or cloudy and only has a thin layer of bubbles on top, then you likely have hard water.

This test is not 100% accurate and can only give you a basic idea of whether you have this issue or not.

Professional hard water testing

For a more accurate and detailed analysis of your hardness level, you can opt for a professional test. These tests not only measure the hardness of your water but can also identify the presence of other potential impurities like lead, bacteria, pesticides, and more.

Professional water testing can be done in a couple of ways:

  • Water testing labs: You can send a sample of your water to a certified laboratory that specializes in water testing. They will provide you with a detailed report of your water quality.
  • In-home water testing services: Some companies offer in-home water testing services. A representative will come to your home, collect a water sample, and then send it to their lab for analysis.
  • Water test kits: You can also purchase a water test kit online or from a home improvement store. These kits usually come with all the necessary tools and instructions to conduct the test at home. 

Professional water testing is more reliable and comprehensive than a DIY test. It can help you understand the severity of your hard water problem and guide you in choosing the most effective treatment solution. It can also alert you to any other water quality issues that may be present in your home.

Conclusion: Choosing the Best Solution for Your Home

With all these options for removing hardness minerals from your drinking water, getting rid of hard water doesn’t have to be…hard.

The best solution for getting soft water in your home will depend on the severity of your hard water problem, your budget, and your personal preferences. It’s important to consider all your options and make an informed decision.

When it comes to water quality, when in doubt, consult a local professional.


Can hardness be filtered out of water?

Yes, hardness can be filtered out of water using water softeners, the most common and effective of which employ ion exchange to replace hard mineral ions with sodium ions or potassium ions. Additionally, reverse osmosis systems can effectively remove hard water minerals.

How do you purify hard water at home?

To purify hard water at home, you can install a water softener system to replace hard minerals with softer ions. You can also use an RO system to filter out hard water minerals. For mildly hard water, add washing soda or vinegar during laundry to combat the effects of hard water. For a short-term solution, boiling water can reduce temporary hardness.

What filter will remove hard water?

A reverse osmosis system is a type of filter that can effectively remove hard water minerals. Additionally, water softeners, while not traditional “filters,” can treat hard water by replacing calcium and magnesium ions with sodium or potassium ions.

How do you remove water hardness from water?

The best way is to install a water softener that employs ion exchange. To get enhanced filtration beyond only water softening, install a reverse osmosis system to filter out hard water minerals.

Additionally, less effective but cheaper methods include conditioning methods like magnetic or electronic water conditioners, which alter the properties of hard water minerals to reduce scaling.

Interested in learning about water filters? Explore their importance in ensuring a reliable water supply as you discover these additional resources:

Notify of

Inline Feedbacks
View all comments