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How to Remove Calcium from Water? – 4 Simple and Reliable Methods

Fact checked by Stephen Conklin

how to remove calcium from water

Calcium constitutes 3.64 percent of the Earth’s crust. Hence, it’s no surprise that this naturally occurring mineral is present in water across the globe. It is a vital nutrient that’s essential for our muscle movement and cardiovascular function.

While calcium provides immense health benefits, it is one of the various dissolved minerals that make water hard. We all know that hard water wreaks havoc on our domestic appliances and plumbing fixtures over time.

As a result, we need practical DIY tips and hacks on how to remove calcium from water. And today, I’ll be discussing straightforward solutions to help you improve your water quality at home: reverse osmosis, chemical treatment, water softening, and boiling.

Table of Contents

4 Simple and Reliable Methods To Remove Calcium From Your Home Water


Most homeowners find it intimidating to remove calcium from water at home. But removing calcium from water supply is as easy as doing minor DIY repairs at your home.

You don’t have to be a water specialist to remedy your hard water at home. Find out what works the best for your hard water problems in the four easiest methods :

1. Reverse Osmosis

You have probably heard about the Reverse Osmosis water purifying system. It’s pretty famous for homeowners because it is one of the most effective eliminators of innumerable impurities in your water.

RO systems’ highly porous membranes make it easier to relieve your water of hard minerals like calcium and magnesium. Hence, they reduce the hardness of your drinking water.

However, RO systems are high maintenance. Each system involves 3-5 filtration stages which require replacement regularly. You would need to change the filters on their respective schedules to ensure that the RO membranes aren’t clogged with hard minerals.

RO membranes should be replaced every 2-3 years but of course, how frequently you change them depends on your household water conditions and usage. Kindly bear in mind that RO systems have a specific maximum scale of tolerance to hard water minerals.

Calcium and Magnesium should be no more than 60 mg per liter of water. On the other hand, iron should be less than 30 mg per liter, and Manganese should be kept at 0.05 mg per liter in your home water.

The smaller the numbers, the better. We should follow these recommended limits to extend the lifespan of the RO membrane.

In addition, hard water can potentially carry bacteria that could contribute to the premature deterioration of the membrane.

A study in 2017 found out that frequent cleaning cycles of microorganisms present in RO membranes impede their performance. Hence, it is advised to use pre-treatment (sediment filter) to remove calcium from well water.

It is highly advisable to disinfect the RO unit periodically using chlorine or other disinfectants instructed by the manufacturer. Please take note of this procedure before considering RO systems for your home.

2. Chemical Treatment

Domestic Chlorination is among the most efficient household water chemical treatments as it disinfects the entire water system, including pipelines and water tanks.

The Centers for Disease Control and Prevention verifies that chlorinated water is safe to drink as long as the content level is no more than four milligrams per liter. However, calcium removal from water isn’t possible with chlorine.

Chlorine will not remove heavy metals such as calcium and magnesium present in your drinking water. But there are other water treatment chemicals you can use to remove calcium from drinking water at home :

  • Washing Soda

Washing Soda (Soda ashes) or Sodium Carbonate is a potent chemical compound used for water calcium removal. You can buy it in grocery stores, hardware/home improvement stores, and pool supply stores.

How does washing soda work in removing calcium from water? It serves as a part of the pre-treatment purification of water. Water is made hard because of calcium ions and magnesium ions.

Soda ashes in your drinking water make it softer because they are soluble. Calcium ions and magnesium ions are insoluble. Therefore, the carbonate and calcium ions will bond to form insoluble precipitates, which will be forced out of your water and slowly soften it.

Add 1⁄2 cup of the washing soda to bathwater and cleaning water. Then, you’re all set. Consider limiting your use to laundry activities as this substance’s not safe to drink.

  • Vinegar

Vinegar is an acetic acid that is used as a reliable cleaning companion for many homeowners. It softens the laundry by removing soap and residue-build up, which will whiten the white fabrics. Additionally, it cleans the dishes well, leaving spotless surfaces.

Given the many wonders of vinegar purposes at your home, it is no surprise it can also treat and filter calcium from water. Just add half a cup of vinegar to the final rinse cycle of the laundry/dishes.

3. Water Softeners

A water softener is an excellent option for families who have been suffering from hard water problems for a long time. Each softener device can filter up to 5 milligrams of calcium.

Please don’t use an activated carbon water filter to remove calcium and lime, as it won’t. Carbon filters only remove odors, pollutants, and volatile organic compounds. Instead, use a calcium water filter with ion exchange resins.

These resin beads will attract the hard minerals and replace them with sodium ions that produce soft water. Your water softener unit will then flush out the excess ions from the system and recharge the unit with new sodium ions.

4. Boiling

Boiling can do amazing results as it can effectively remove temporary hardness in your tap water. Yes, you read that right — it’s only temporary. It doesn’t remove all hard minerals present in your residential water.

If you’re on a tight budget, boiling is the least expensive treatment you can do for your hard water. It’s easy, and you can do it alone without any further assistance. All you have to do is to bring a pot of water to a boil for 10 minutes.

Boiling will only remove carbonate hardness: calcium carbonate, and calcium bicarbonate. When the water reaches its boiling point, you will notice sediments in the pot. After boiling, remove the water from heat and allow it to cool down for several minutes.

Lastly, strain the water to pick up excess impurities and mineral residues. Voila! Your water is now ready to use.

Are There Any Health Effects Associated with Drinking Hard Water


The World Health Organization reported that drinking hard water can give you calcium & magnesium. According to health experts, hard water has no known adverse health effects on our bodies.

We both need calcium and magnesium for our bone health. Maintaining adequate levels of these minerals will prevent us from contracting bone diseases such as Osteoporosis. While most researchers focus on Calcium as the major element that is responsible for muscle function, Magnesium balances the calcium supply of our body.

Hard water can help us maintain our optimum health at some point. However, it will negatively affect our skin and hair. Hard water will alter the pH level of our skin, leading to weak defense barriers against bacteria and infections.

Washing our hair with hard water regularly will make it difficult for moisture to enter, leaving our hair dry and scalp itchy. Thus, it is crucial to choose a water treatment that will create favorable conditions for you and your family.


Hard water is quite a mood killer in our domestic water consumption every day. As much as we are excited to take a bath, we know it will strip away the natural moisture from our skin. Hence, it is always necessary to learn how to remove calcium from water.

Now that you have gained insights about it, I’m confident that you could solve your long-vexing hard water problems alone. If there are any water treatment topic requests, don’t hesitate to share your thoughts in the comment box below. Learning never stops, and so is DIY!

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