Reverse osmosis (RO) is often considered one of the best ways to filter water. It is one of the many ways to bring crisp, fresh water to your home. RO’s unique process pushes water through a semipermeable membrane, which separates pure water from everything else, such as chemicals and bacteria. The membrane is made so that only the water molecules can fit through it, which is why the water that comes out of RO is so clean.
Because of the RO purification process, added elements to the water are also separated. That may leave you wondering – does reverse osmosis remove fluoride?
In this article:
Understanding Fluoride in Water
Fluoride likely sounds familiar because you’ve heard it at the dentist. Whether you’ve been offered fluoride foam or something else, it’s commonly associated with oral health. This naturally occurring mineral keeps teeth strong and prevents tooth decay, which is why it’s added to our public water supply. This water additive began in 1945 in Grand Rapids, Michigan, as a means to keep children’s teeth healthy, and it has been used ever since.
Potential Risks of Fluoride Overexposure
While there are benefits to water fluoridation, there are also drawbacks to having too much fluoride. These drawbacks are enough that many countries ban fluoride from their drinking water. Most of Western Europe, for example, has that ban in place, including countries like Germany, Iceland, Sweden, and Switzerland, per the National Institute of Health (NIH).
Some of the potential risks of fluoride exposure include:
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- Cognitive impairment
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- Reproductive issues
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- Risk of dental fluorosis (a build-up of extra fluoride, tooth pitting, discoloration, etc.)
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- Skeletal fluorosis (fluoride build-up in bones causing joint issues, weak bones, etc.)
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- Thyroid dysfunction
How Reverse Osmosis Works
As a water filtration process, reverse osmosis filters contaminants out by forcing the water through a semipermeable RO membrane, which only allows water molecules to get through. These membranes are usually made of cellulose acetate (cellulose-based plastic) or polysulfone (thermoplastic).
According to the CDC, RO systems are highly adept at removing heavy metals, dissolved solids, viruses, bacteria, and parasites from water. They are also excellent at removing certain chemicals, including arsenic, radium, and nitrates.
Does Reverse Osmosis Remove Fluoride?
Reverse osmosis is an effective water filtering method because its semipermeable membrane does not allow the majority of contaminants through. RO is considered the best filter for removing the most fluoride from water, though it may not remove all of it.
According to research from the NIH, there are several factors that affect the full removal of fluoride from water through filtration. These factors include the amount of fluoride present, the pH of the water, water pressure, temperature, surface area, and particle size, to name a few.
Particle size is especially impactful in this case because of how reverse osmosis works. It works by pushing molecules through a membrane that only allows certain-sized molecules through with the water.
Comparing Reverse Osmosis with Other Fluoride Removal Methods
While reverse osmosis is widely considered the most effective method of removing fluoride from water, other effective methods include alumina filters, bone char carbon filters, and distillation.
Activated Alumina Filters
A water filter with alumina inside essentially absorbs contaminants to neutralize them from the water. Because alumina is highly porous, it can draw things like fluoride, arsenic, and selenium from water. This differs from RO because it doesn’t use a mesh-like substance to separate the water from contaminants. Instead, the alumina filters essentially trap the contaminants inside.
Bone Char Carbon Filters
Similarly to alumina filters, bone char carbon filters use their porousness to absorb fluoride and other contaminants. They can do this through an ion exchange. In this exchange, the bone char ions snatch up the fluoride ions and keep them out of the water as they pass through the filter.
Distillation Process
Water distillation is very different from any of the filtration methods mentioned so far. It relies on heat to separate contaminants from water. It does so by boiling water, allowing it to evaporate, collecting it, and allowing the steam to become a liquid again. When this happens, the contaminants do not evaporate and are left behind.
Pros and Cons of Using Reverse Osmosis for Fluoride Removal
Advantages of Reverse Osmosis Systems
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- Energy efficient
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- High fluoride removal
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- Improved drinking water quality
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- Reduces other contaminants and hard water minerals
Disadvantages and Limitations of Reverse Osmosis Systems
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- Maintenance is necessary
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- Removes other minerals that can be beneficial
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- Water waste (5 gallons of waste for every gallon produced)
Maintaining Your Reverse Osmosis System
As excellent as a reverse osmosis water filtration system can be, it still requires routine maintenance. For example, the system has three filtration sections: sediment pre-filter, carbon pre-filter, and the membrane. Both pre-filters need to be replaced every six to twelve months, while the membrane should be replaced every two years.
You will also want to sanitize your entire RO system yearly to stop buildup and backup. That means flushing the whole system to keep it running efficiently. Your top indicator for a system not running efficiently is a slowed water flow, bad smell, or noticeable leaking. With any issues or maintenance needs for your reverse osmosis system, be sure to contact the experts at LeafHome!
FAQs About Reverse Osmosis and Fluoride
How Often Do I Need to Replace My RO Filters?
Both the sediment pre-filter and the carbon pre-filter should be replaced every six to twelve months. However, the membrane itself can often last up to two years.
Does Reverse Osmosis Remove All Fluoride from Water?
Reverse osmosis systems are the best way to help reduce fluoride from water. However, they do not remove all fluoride. RO is known to remove over 90% of fluoride, which makes it an efficient way to have highly filtered drinking water at home.
Is RO Water Safe for Children After Fluoride Removal?
RO-treated water is absolutely safe for children. It removes fluoride, which can cause dental and skeletal fluorosis (particularly in children), though it also removes important minerals too. RO is a highly effective filtration system that removes fluoride as well as other minerals like calcium, magnesium and potassium from the water. Unfortunately, these minerals are highly beneficial for growing children.
