Does Reverse Osmosis Remove Fluoride From Drinking Water? My Data

Does Reverse Osmosis Remove Fluoride From Drinking Water? My Data

Are you concerned about fluoride in your drinking water? If so, you may be asking – does reverse osmosis remove fluoride.

Fluoride is a mineral that’s naturally found in soil and groundwater. It’s also added to some public drinking water supplies as a way of preventing tooth decay. However, there are health concerns associated with fluoride exposure.

Reverse osmosis (RO) is one of the best ways to remove fluoride from your tap water. The EPA lists reverse osmosis as a very effective treatment method for fluoride. RO systems can remove between 84% to as much as 99% of the fluoride in drinking water. Reverse osmosis systems must be properly maintained, or fluoride removal efficiency can decrease.

One concern with reverse osmosis is that it creates aggressive water that can corrode copper pipes and other plumbing fixtures.

Continue reading to learn more about how reverse osmosis removes fluoride from your drinking water.

Fluoride – What Is It and Why It Matters

What is Fluoride and Do You Need It

Fluoride is one of the most common additives used in public water supply systems. It is present in most drinking water – both tap and private potable well water.

What is fluoride and why is it so controversial?

What is fluoride?

Fluoride is a mineral that occurs naturally in rocks and minerals. It readily dissolves in water, does not have any taste or odor when dissolved into solution, and has no color in water. Fluoride is also found in soil and groundwater.

There are two types of fluoride: calcium fluoride, a natural ionic compound which contains calcium ions, and hexafluorosilicic acid, an industrial chemical that has been added to drinking water supplies for decades.

Why is fluoride in my drinking water?

Water treatment plant - adding fluoride
Fluoride is the most common additive used by public water utilities in the US.

Fluoride is naturally present in some groundwater. If you get your drinking water from a well in one of these areas, it may contain fluoride.

Fluoride has been added to public water supplies in the United States for more than 70 years. Fluoridation was started after researchers discovered that people who lived in areas with naturally high fluoride levels had significantly fewer cavities.

The American Dental Association is a strong advocate for fluoridation. They feel that the proper amount of fluoride in community water is appropriate and effective in preventing tooth decay by at least 25% in both children and adults.

Health concerns over fluoride

Many people have begun to challenge the need for adding fluoride to public water supplies. They point out:

  • Fluoride has been linked to negative effects at low doses
  • Many children get the recommended daily fluoride dose from toothpaste
  • Fluoride can bioaccumulate, degrading the structure of bones, making them brittle and vulnerable to fracture.
  • Fluoridation may be harming the environment because nearly all of our water supply is not consumed but instead discharged down the drain.
  • According to a study published in The Lancet, water fluoridation may raise the risk of hypothyroidism, or underactive thyroid.

Fluoride drinking water standard

There is no federal drinking water standard (i.e., safe level) for fluoride. To avoid dental fluorosis in children, the United States Department of Health and Human Services recommends that fluoride in drinking water be limited to 0.7 mg/L.

How Reverse Osmosis System Removes Fluoride from Water

Reverse osmosis filtration is one of the most effective methods for removing fluoride from drinking water. Reverse osmosis systems use a semipermeable membrane to remove minerals and chemicals from the source water – including fluoride.

Fluoride is not able to pass through the membrane and is filtered out from the water. Purified water passes through the membrane and the fluoride and other contaminates are removed from the water.

Reverse osmosis filters – how they work

Reverse osmosis works by passing contaminated water through a permeable membrane. The membrane is a plastic sheet that has thousands of tiny holes, called pores, designed to filter out contaminants.

The membrane pores are very small in diameter – 0.0001 microns is typical for most RO membranes. Water is pumped through the membrane under pressure: the water passes through the membrane and larger particles and molecules are filtered out. This results in pure water passing through the RO filter and a concentrated solution of contaminants, called brine, produced as waste.

Reverse osmosis water filter systems

Undersink reverse osmosis system

I recently installed a great RO system in my kitchen. This undersink unit is great – it was easy to install, it is easy to maintain, and it removes a lot of contaminants, including fluoride.

You may want to install one in your home, too.

Check Pricing on Amazon

The Thunder Ultrafiltration/Reverse Osmosis Water Filter (CQE-RO-00101) offers 12 filtration stages for high-quality drinking water. Key features include:

  1. 5-micron carbon cartridge: VOCs, pesticides, and larger particles
  2. 0.020-micron Ultrafiltration membrane: bacteria, viruses, and organic molecules
  3. 1-micron filter pads for suspended particles like silt and rust
  4. Granulated activated carbon for organic contaminants and odors
  5. Ion exchange resin for heavy metals and water hardness
  6. Eagle Redox Alloy® media for oxidizing contaminants and preventing bacterial growth
  7. CRYSTAL QUEST® reverse osmosis membrane for inorganic contaminants

The system has a 50-gallon daily capacity and includes a full installation kit with a designer faucet, stainless steel holding tank, color-coded tubing, and cartridges. Optional filters are available for specific contaminants like fluoride and nitrates.

Fluoride Removal Using Reverse Osmosis

Fluoride can be readily removed from drinking water using reverse osmosis filtration. Reverse Osmosis units are very efficient at removing an average of 95% or more of the fluoride in drinking water.

Another benefit – reverse osmosis filters don’t only remove fluoride from your water supply

How well does RO remove fluoride from water?

Several studies have been conducted on reverse osmosis for fluoride treatment. They found that RO filters can remove a significant amount of fluoride. Treatment effectiveness ranged from a low of 85% to as much as 92% of the fluoride was removed.

My testing results for reverse osmosis

I tested my reverse osmosis filter to see how well it removed fluoride from my tap water. I have an under-sink reverse osmosis filter in my kitchen. My drinking water comes from the town water supply, and they add fluoride to our water.

To see how well my RO filter removes fluoride, I collected a sample of both the untreated tap water and the water that came out of the RO filter. I sent the sample to a state-certified testing laboratory and had them run the sample for fluoride. Read my comprehensive article on how to evaluate your RO system’s performance.

The influent fluoride concentration of my tap water was 0.93 mg/L. The treated water fluoride concentration was 0.046 mg/L. Based on this sampling event, the fluoride removal efficiency of my RO filter is 95%. Reverse osmosis will filter out fluoride effectively.

Disadvantages of Using RO to Remove Fluoride

One concern with reverse osmosis is that it creates aggressive water that can corrode copper pipes and other plumbing fixtures.

Water that has been treated with a reverse osmosis system contains nothing but pure H20 molecules. Reverse osmosis is 99% effective at removing minerals, chemicals, contaminants and pollutants. The absence of essentially all dissolved solids results in water that is very corrosive. If your pipes are constructed of copper, iron, or other metals, the RO water can cause severe corrosion.

Some people find that water treated with reverse osmosis has a metallic, salty, or earth taste. One solution to this issue is to use a remineralizer to add back minerals like calcium and magnesium.

Features to Consider for RO Treatment of Fluoride

If you decide to remove fluoride from your drinking water with reverse osmosis, there are a few features you should consider.

Make sure the RO filtration system has the following components:

  1. Pre-filter (sediment filter): this filter removes turbidity, suspended solids, and other solids to protect the RO membrane from being fouled.
  2. Carbon adsorption filter: this filter uses activated carbon to remove chlorine and dissolved solvents that can break down and degrade the RO membrane.
  3. Post-filter: this filter uses activated carbon after the RO membrane to improve the taste and quality of the treated water.

Best type of RO filter for fluoride removal

countertop reverse osmosis filter to remove fluoride
A countertop reverse osmosis filter like this one can remove 90% or more of fluoride from tap water.

Reverse osmosis filters come in several configurations. Selecting the best one for treating fluoride in your water is an important consideration.

  1. Under-sink RO filter: this is the most common type of RO system, and it is installed under the kitchen sink. It has a small footprint and is easy to use.
  2. Countertop RO filter: this type of filter sits on the countertop and has a larger capacity than an under-sink unit. It is ideal for households with multiple people who drink water from different sources. [learn more]
  3. Whole-house RO filter: this type of system is designed for whole house water filtration and can service an entire home or apartment building with fluoride-free drinking water.

With any reverse osmosis unit, it is very important to ensure that the filters are replaced when recommended by the manufacturer. This ensures that your treated water doesn’t contain contaminants that could negatively impact your health.

The key takeaway – RO does remove fluoride.

Other contaminants to treat

When selecting an RO filter to remove fluoride from your drinking water, you need to know if there are any other contaminants that you want to treat. This might affect whether you select an under-sink filter, which would just treat the water your drink and cook with, or a whole-house system.


You need to establish a budget for your water treatment needs before you start the project. This includes the cost to purchase the reverse osmosis water filter as well as any installation costs.

RO filters range in price from around $100 to several thousand dollars. The most expensive filters are for whole-house systems, but there are many affordable options for under-sink and countertop units.

Installation costs also vary depending on the type of filter you select and whether you have a professional install it or do it yourself. Generally, installation costs range from $200 to several thousand dollars.

Once you have determined the cost of the filter and installation, it is important to factor in the monthly operating costs as well. Most RO filters require replacement filters every six months to a year, which should be added to your budget.

Test Your Drinking Water for Fluorine

Fluoride Water Test Kit
Tap Score has a simple to use test kit to measure fluoride in your drinking water.

Tap Score offers a laboratory test to measure the level of fluoride in your drinking water. This package provides all the necessary materials to collect and submit a sample for testing. Results will include a detailed, quantified analysis of fluoride levels in your water.

Knowing what’s in your water is the first step to keeping your family safe.

Order your Tap Score Fluoride test kit today

Frequently Asked Questions (FAQs)

Do Brita filters remove fluoride?

Brita filters are not effective against fluoride. They use activated carbon and particulate filters to purify water, but these technologies do not remove fluoride

Does boiling water remove fluoride

Boiling water does not remove fluoride. In fact, boiling water may actually increase the concentration because some of the boiled water will evaporate, and the remaining fluoride will be more concentrated.

If you are looking for a way to remove fluoride from your drinking water, reverse osmosis is the most effective method.

Do refrigerator filters remove fluoride?

Refrigerator filters do not remove fluoride. They remove particulates, chlorine, and other contaminants to make the water taste better. The only type of filter that can remove fluoride is an RO system. Read my comprehensive on refrigerator filter treatment performance.

Do activated carbon filters remove fluoride?

Activated carbon filters do not remove fluoride. Fluoride is an ion, and it does not adsorb to carbon particles. The only filtration method that removes fluoride is reverse osmosis.

Do Clearly Filtered Filters Remove Fluoride?

Yes, Clearly Filtered filters are capable of removing fluoride from drinking water. The company’s filters use a proprietary blend of activated carbon and other filter media, which are designed to remove a variety of contaminants, including fluoride. The filters are independently tested and certified to NSF/ANSI standards, which include testing for fluoride reduction.

Final Take on Reverse Osmosis for Fluoride Treatment

Fluoride is a mineral that can be found in most drinking water. It’s been added to community water supplies since the 1950’s because it helps prevent tooth decay. However, there are concerns that too much fluoride over time can cause dental fluorosis or bone damage in young children.

Reverse osmosis is a water treatment process that can remove fluoride from drinking water. Testing indicates that 85 to 92% of fluoride can be removed with RO filtration. Reverse osmosis is a proven technology that is well understood, and you can be confident that it will remove fluoride from your drinking water. Reverse osmosis water is a safe solution to your fluoride concerns.

Boch Richard

Richard Boch is a chemical engineer responsible for designing water filtration systems for industrial and residential customers. He has more than 20 years of experience with ion exchange, activated carbon, and reverse osmosis. Richard's expertise has made him a go-to source for municipalities and businesses looking to improve their water quality. When he's not working, Richard enjoys spending time with his wife and two young children.

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