Do Water Filters Remove Calcium [What’s The Best Way?]

Should Your Water Filters Remove Calcium?

Calcium is just one of the many contaminants in our water. Humans require the healthy mineral calcium to survive. However, limescale, a harmful coating left on surfaces by calcium in your tap water, is present. Hardness can cause scaling tubs, clogged dishwashers, and strange flavors in your water.

Hard water can shorten the lifespan of many of your appliances and fixtures if it is not treated. Water hardness is typically caused by the mineral calcium, which is primarily found in groundwater. Low calcium concentrations may not significantly harden water, but a range of 100 to 500 ppm can.

To remove calcium from water, many people think about using a good whole-house water filter, but does it work? We’ll discuss what we know about calcium removal from whole house water filter systems in this guide, including if any particular types of filters can remove calcium and our suggested technique for doing so.

Where Does Calcium Come From?

Calcium dissolves from a variety of rocks, including apatite, fluorite, limestone, marble, calcite, gypsum, and dolomite, and it is found in water naturally.

Overall, rocks, especially gypsum and limestone, are the main source of calcium.

How to Measure Calcium in Water?

It is essential to understand what water hardness is before talking about how to measure calcium in water.

Depending on the amount of calcium carbonate present, water is classified as soft, moderately hard, or hard.

Calcium levels in water are typically expressed as gpg (grains per gallon), mg/L (milligram per liter), or ppm (parts per million) (parts per million). The first is the norm in the field.

  • You must divide mg/L or ppm by 17.12 in order to convert them to gpg. So as to:
  • 1 ppm = 1 mg/L, and 1 gpg 17.12 ppm = 17.12 mg/L.

Here’s how to determine how much calcium is in your water.

Send a water sample to a reputable lab after collecting it. A lab expert will analyze your water for calcium levels and provide you detailed results.

Additionally, you can ask for a free water quality report from your local water provider (only if you use municipal water). Reports on water quality are typically available online. Other than that, speak with the utility directly and ask.

Finally, you can check your own calcium levels. All that is required is the purchase of a DIY testing kit. DIY test kits can be purchased for under $20.

Although you may check the calcium levels in your water yourself, we strongly advise sending a sample to a reputable lab. Yes, the process will cost money and take time, but a lab expert conducts tests in accordance with rigid industry standards. In addition, the reports are accurate, which may be all you require.

Why Is Calcium in Water a Problem?

Let’s be clear: Calcium is not a life-threatening condition. However, having too much calcium in your water source can cause a few issues.

  • Surfaces in the kitchen and bathroom get up tough stains from hard water. The stains typically appear when limescale is left behind after water evaporates.
  • Water with high calcium levels dries out the skin and tangles hair. You can also have itching and dandruff on top of that.
  • Calcium buildup in pipes can lower flow rates, eventually leading to leaks and possibly necessitating expensive replacements.

Over time, washing items in harsh water can fade the color of the fabric. With hard water, several synthetic cleaners lose some of their effectiveness. Why? Due of the hardness of the minerals, the active ingredient in cleansers becomes inactive.

Health Effects of Calcium

As previously mentioned, calcium in water can discolor sinks, faucets, and bathtubs. Additionally, it could result in dry skin.

However, consuming calcium through water has no negative consequences on one’s health. Instead, health professionals view it favorably. For instance, research indicates that patients with osteoporosis can have increased bone mass growth and decreased bone loss when they consume enough calcium.

Do Water Filters Remove Calcium?

To remove a particular collection of contaminants, including chlorine, heavy metals, volatile organic compounds, and other dangerous substances, a water filtration system often employs numerous filter stages.

Calcium removal from water is not a function of the typical whole-house water filter. However, some whole house water filters have micron ratings low enough to capture big calcium particles, helping to somewhat reduce the amount of this mineral in water. Ever wondered do Brita filters remove fluoride? Do check out our separate article on it that you may find helpful.

Do Water Filters Remove Calcium and What Types of Water Filters Are Effective for Calcium Removal?

It’s crucial to understand that there are no such things as calcium water filters. There aren’t any whole house water filters designed specifically for removing calcium. That’s because the majority of filtering methods, such as activated carbon and KDF, are unable to get rid of this hard water mineral.

The best calcium water filter is only an extra benefit; it wasn’t made to filter calcium. Ultrafiltration and reverse osmosis filters are the two filters that can lower calcium.

Reverse Osmosis

A semipermeable membrane, which is made up of microscopic pores and found in reverse osmosis whole house water filter systems, traps the bulk of impurities, including calcium and magnesium.

Calcium is drawn into the RO chamber because it is too big to pass through the RO membrane. Here, a small amount of wastewater is used to flush calcium and other impurities down a drain.

Between 92% and 98% of the calcium carbonate and magnesium minerals from drinking water can be eliminated by a reverse osmosis system. Looking to ge a reverse osmosis sytem for yourself, you’ll love our article on how much does a reverse osmosis system cost?


Like reverse osmosis system technology, ultrafiltration is a membrane filtration method that use a hollow fiber membrane to capture impurities as small as 0.01 microns. Although UF membranes can still remove calcium from hard water, they cannot remove pollutants as tiny as RO membranes can.

A 50% calcium removal rate is possible using an ultrafiltration system for drinking water. An ultrafiltration system does not guarantee that calcium will be removed from your water; some UF systems promise calcium removal while others do not.

Are There Any Disadvantages of Using Water Filter to Remove Calcium?

To lower calcium, we wouldn’t advise using any kind of whole-house water filter. Although this mineral can be removed using a reverse osmosis system, that is not what they are made to do.

A harmful mineral called calcium will adhere to whatever surface it comes into contact with, even RO membranes. A filtration membrane loses effectiveness and can no longer remove impurities as efficiently as it should when calcium starts to create scale deposits on it.

Reverse osmosis under-sink water filters for calcium reduction will probably lead the membrane to become less effective before it reaches the end of its anticipated lifespan. Because of this, the majority of ultrafiltration and reverse osmosis systems call for pre-treatment to lower calcium and magnesium levels before they may be introduced.

The reduction of calcium in your water by a whole-house water filter is not guaranteed, and it won’t result in fully soft water. Calcium may only be slightly reduced by RO and may not even be removed by ultrafiltration. Whole-house water filters aren’t made for reducing calcium, plain and simple.

Best Methods to Eliminate Calcium From Water

Water Softener

Utilizing a water softener is the most effective approach to remove calcium from water.

The only purpose of water softener systems is to soften hard water. Ion exchange, which removes calcium using a water softener, replaces calcium and magnesium with minerals that don’t contribute to scale, including sodium or potassium ions.

In order to treat water before it enters your water heaters, a water softening system is installed at the point of entrance into your home. As a result, your home’s hot and cold water will be softened.

Water softener systems entirely eliminate water hardness, avoiding limescale formation for years, in addition to lowering calcium concentrations.

A whole-house water filter is set up differently from a water softener. Water softener systems require routine salt top-ups in order to function, whereas filtration systems include cartridges that must be changed.

A water softener typically costs between $1,000 and $2,000. A salt-based water softener is a wise purchase if you’re seeking the best calcium water filter to handle hardness minerals.

Water Conditioner

Looking for a more powerful method to combat water hardness than a whole-house water filter but don’t want to add salt to your water?

Another efficient method of calcium water treatment is a good salt-free water conditioner. This technology uses a crystallizing procedure to stop hardness minerals from adhering to surfaces and producing scale, such as template-assisted crystallization.

Water conditioners don’t actually remove calcium from your water, so your water quality won’t change and you’ll continue to get the same daily calcium need from your water. This is a key distinction between water conditioners and water softener systems. Your water’s calcium and magnesium ions won’t be able to produce scale deposits, nevertheless.

Water conditioners cost about $1,500-$2,200. They’re not quite as effective at tackling scale-forming calcium as salt-based systems, but they’re much more effective than whole house water filter systems.

Boil Water

Strong or hard water contains a high concentration of dissolved minerals, primarily calcium and magnesium. The presence of a large concentration of minerals is indicated by the hardness of the water.

Hardness in water cannot be permanently removed by boiling it. It is able to purge water of calcium and bicarbonate ions. The elimination of sodium and magnesium ions, which cannot be totally removed by just boiling the water, can remove the permanent hardness of water.

Magnesium ions are somewhat removed from boiling water but not entirely. The precipitate, which is composed of calcium and bicarbonate ions, forms during the boiling process and separates from the clear water. This suggests that water can become somewhat softer after being heated to a boil.

So, we can conclude that boiling water causes calcium and magnesium carbonate to precipitate out. It is removed from the clean water and takes the hardness out of the water. As a result, heating water briefly reduces its hardness.

To make drinking water softer, boil it. Ten minutes after bringing a pot of water to a boil, let it cool. Some types of carbonate hardness, or calcium mineral deposits, are removed when water is boiled, but not all varieties. Calcium carbonate, calcium bicarbonate, and calcium hydroxide are carbonate hardnesses that can be removed from drinking water by boiling.


Why is calcium in water bad?

Although excessive calcium can cause limescale to accumulate in pipes and water-based appliances, calcium in water is perfectly safe to drink. Calcium is a hard water mineral that can cause buildup in your plumbing, on your showerhead, in your toilet, around your faucets, in your dishwasher, and in your washing machine.

The efficiency of products like your hot water heaters can be negatively impacted by limescale, which is why limescale removal is the only way to stop scale formation.

How much calcium does the Brita filter remove?

No, neither the Brita LongLast nor the Brita Standard filters can lessen calcium ions.

How can extra calcium be taken out of water?

Consider adding a water softener to get rid of extra calcium from the water. Consider using a shower filter that can lower hardness if all you want to do is get rid of extra calcium from your shower water and you don’t want to soften the water in your home.

Do water filters eliminate the minerals in hard water?

No, most filters, including KDF and activated carbon filters, cannot get rid of the minerals in hard water. A calcium filter for hard water does not exist. Small enough pores in some filters, such reverse osmosis system units, can minimize some hardness, but excessive hardness can harm the RO membrane.

Can calcium be removed by any whole house water filters?

A few filters do indeed remove calcium from water. For removing calcium, reverse osmosis and ultrafiltration are the best filters. But keep in mind that a lot of calcium in your water supply will shorten the whole house water filter’s lifespan by damaging the membrane.

How can calcium be removed from household water?

A water softener, which exchanges calcium for sodium ions instead of limescale-causing calcium, is the best tool for removing calcium from whole-house water.

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