How to Remove Calcium from Water

Here’s how to remove calcium from water for softer H2O.

There are two types of water, and though they seem the same at first glance, their effect is significantly different. Soft water is low in minerals, while softened water usually only contains sodium. Hard water is high in mineral content, with calcium — and to a lesser degree, magnesium — at the forefront (1).

Hard water isn’t detrimental to your health, but it can interfere with your lifestyle, plumbing, and home. It’s deemed safe to drink, but it can damage your faucets and dampen the effects of your grooming, beauty, and skincare products.

What’s great is that you can change the hardness of water with little difficulty. We’ll show you how!

What Makes Water Soft?

Water in its purest and most natural form — like the ocean or rain — is soft. As it flows over, or through, the ground, rocks, and other high-mineral materials, it picks up traces of calcium and magnesium.

Hardness is measured by the volume of these minerals, in this case, calcium. Water with less than 17 milligrams of calcium per liter is considered soft.

If the water has between 17 and 60 milligrams per liter of calcium, it’s slightly hard. Between 60 and 120 milligrams per liter, it’s moderately hard, while 120 milligrams and higher per liter is considered very hard (2).

How to Tell Hard Water from Soft

The easiest way to determine if your home’s water is hard is to drink it. You can taste the minerals in hard water, just as you can taste the sodium in soft water. When hard water is softened, people describe its taste as flat and somewhat salty.

Hard water leaves a residue. When it evaporates, calcium and other minerals won’t evaporate with it. They’ll return to their solid form and settle wherever they’re deposited — this is what causes limescale around your home.

Hard water can affect your household and grooming products too. They won’t lather as much, and so may not be as effective as they are in soft water. Hard water can also leave a white residue on your skin.

How is Hard Water Softened?

There are several ways that water is softened, but most methods are used industrially or commercially.

Ion-Exchange Resin

This is achieved by attaching a water softening device directly to your supply. These containers hold ion-exchange resin or beads that switch out hard molecules for soft ones. In this process, calcium and magnesium are replaced with sodium and sometimes (but rarely) potassium.

Calcium Hydroxide

Calcium hydroxide is a powder used to treat and prepare water, food, and paper. It purifies water and is used to raise the alkalinity of freshwater to prevent rust.

This method is typically reserved for industrial use, as improper handling of calcium hydroxide is dangerous.


Distillation is an effective but expensive method of water softening. As water is heated, it evaporates and leaves hard water ions behind. The only problem is that the energy required to maintain the soft water result isn’t worth it in a residential context.

Chelating Agents

Chelators — molecules that easily bind to metal molecules — can remove calcium and magnesium from water. These substances are commercially added to cleaning products, like shampoos, soaps, and detergents.

Though they’re prominent in their respective industries, they have an environmental impact, and so are losing favor as water softeners.

Reverse Osmosis

Reverse osmosis uses controlled pressure to isolate hard water ions. Purified water is then pushed through a filter, leaving calcium and magnesium behind.

An advantage of this method is that it doesn’t replace hard water ions with new molecules. A drawback is that reverse osmosis machines need regular maintenance, or else they’ll lose their effect.

Know The Difference

Don’t be fooled by non-chemical water softening methods, as this is considered conditioning rather than softening. Chemical methods mean that water is altered on a molecular level to get rid of hard ions. Non-chemical solutions may lessen the effect of hard water but won’t turn it soft.

How to Remove Calcium from Water

There are many reasons you may want to soften your water supply. Whether it’s for grooming, your household, or protecting your clothes or kitchenware, you can try a few methods at home.

Here’s how you can go about treating your hard water efficiently and quickly:

Use a Water Filter

The simplest and most convenient method to soften your water is to use a water filter. Most use activated carbon to absorb and trap contaminants. They’re capable of filtering an array of impurities, from chlorine to heavy metals.

You’ll have to spend a bit of money on a filter, and they require installation. Their biggest benefit is that they don’t only soften your supply, they clean it too. This is an example of reverse osmosis.


  • No effort is required.
  • Water is purified and so safer to drink.
  • A popular choice, so easy to find.


  • Filters need replacing.
  • Smaller filters won’t protect your plumbing.

Chemical Treatment

You don’t need a Ph.D. in chemistry to treat your water. All it takes is some sodium carbonate or washing soda. Adding this to hard water breaks down and removes calcium and magnesium from your water supply.

Chemical treatment can protect your pipes and is safe when used as intended. But, the biggest problem is that it’s a cleaning agent and so is not safe for consumption (3).

There are other chemicals that you can use to clean, purify or soften water. These aren’t easy to acquire or use and are typically reserved for water treatment plants (4).


  • Best for maintenance.
  • Removes all traces of calcium.


  • Not safe for drinking.
  • Water Softeners

Water Softeners

A water softener gives you the same effect as chemical treatment, without adding harmful substances to your supply. It’s a device that replaces calcium and magnesium with sodium to change the structure of your water.

Once this exchange takes place, the softener will filter out calcium and other impurities. You’re left with cleaner soft water, and there’s no effort on your part. These machines are the popular choice in ion exchange.


  • Safe to drink.
  • Cleans your water supply.
  • Automated.


  • Installation required.
  • Costs more.

Boil Your Water

Heat will separate the minerals from water. Traces of calcium and other impurities will settle at the bottom of your container and are easily removed with a strainer. This method might require the least thought, but it’s not effective on a larger scale.

The upsides are that no chemicals or devices are necessary, and it leaves your water safe for all uses as well as ingestion. It’s distillation, so keep in mind that while it’s highly effective, it might cost you.


  • Easy to do.
  • No special tools needed.
  • Safe to drink and use.


  • Uses more energy.
  • Only useful for small quantities of water.

Should You Soften Your Water?

Hard water reduces your salt intake and is a sufficient source of calcium for those who can’t acquire it through food. Research shows that it may have a positive effect on cardiovascular health (5). Calcium in hard water is also better for your teeth and bones, especially to children.

Softening your water has its time and place, but sometimes hard water is better. An example of this is your pool. Though soft water feels better on your skin, it can damage the integrity of your swimming pool’s walls (6).

No More Hard Times

Softening water doesn’t have to be a pain and isn’t always necessary. It’s not true that hard water is bad for you, or that soft water is healthier. On the contrary, hard water is recommended for health.

Now that you know how to remove calcium from water, which method are you most eager to try? Tell us why you prefer soft water, and let us know if our tips work for you. Leave us your thoughts and questions in the comments section!

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About the Author

Peter Gray

Peter has been a homeowner for 35+ years and has always done his own repair and improvement tasks. As a retired plumber, Peter now spends his time teaching others how they can fix leaks, replace faucets, and make home improvements on a budget.