Do Residential Carbon Filters Remove Fluoride?

Water filter and glass of water placed on table in garden

Seeking to implement a water filtration system comes with first seeking information about the water quality and what contaminants filters can remove.

One of the more controversial elements of tap water is fluoride, not because of its dangers but due to how it got into drinking water in the first place. There is sometimes a general consensus that all water filters are the same and that they do the same job regardless of type. This, however, is not true, and when it comes to removing fluoride, it can be even trickier. 

What is Fluoride?

Fluoride is a mineral that has positive effects on tooth decay. Fluoride strengthens the enamel on the teeth. Refined carbohydrates and sugar cause the production of acids which draws out minerals from the teeth surface, which leads to cavities. Fluoride then remineralise the teeth’s surface thus preventing the formation of cavities. This is the main reason why toothpaste contains fluoride.

Fluoride in Tap Water

Municipalities have started adding fluoride to drinking water to help with tooth decay. Fluoride was first added to water in 1945 in the US and in 1964 in the UK. The overall results of this scheme have been positive, especially in preventing tooth decay in the children population. 

Stream of water into glass from chrome tap in kitchen

But here is also where the dispute around fluoride in drinking water became apparent. Many households wished to be free of this mandatory fluoridation as they believe it unnecessarily exposes them to unwanted amounts of the mineral. Since fluoride is already in use in toothpaste, the wish is to be free of it in drinking water. 

Fluoride Removal

Since there is no way to be excluded from the fluoride scheme, households have taken to removing fluoride on their own. Looking on the market there are a number of filtration and purification systems that promise to remove a myriad of contaminants. 

Carbon Filters

One of the most commonly used filter medium is absorption-based carbon. This type of filter is also referred to as charcoal or activated carbon, and it comes in many forms. Either carbon granules or a solid carbon block has been used in water filtration. Carbon is used in water pitcher filters, under-sink, and whole-house filters respectively and they can remove chlorine, pesticides, and nitrates. 

Opened activated carbon water filter

When it comes to fluoride, however, carbon is not effective. As much as carbon filters have made their way into a vast majority of filtration systems, fluoride is not among the components it can remove. But it’s also not the only substance that it cannot remove. Dissolved solids, magnesium, sodium, calcium, and certain microbiological pollutants, all make the list of substances that carbon filters can’t take out.

This is not to say that carbon filters are worthless, as in combination with other mediums they do clean other impurities. All this will inevitably come with the question of what exactly can one use to remove fluoride?

Reverse Osmosis

The most prominent water cleaning tool mentioned everywhere as the best option is a reverse osmosis one. Easily the most efficient at purifying water, an RO system uses a semipermeable membrane along with a water pump to forcefully press water through. This method can guarantee anywhere between 85% to 95% reduction in fluoride. 

It’s not a total removal but a substantial reduction in fluoride nonetheless, which is why RO is the best fluoride water filter on the market. RO systems can usually come with their own carbon cartridge filtration system, as an added layer of treatment. It encapsulates more than one type of purification in line with a household’s needs, in the name of practicality. 


As much as fluoride has proven itself to be beneficial for maintaining teeth healthy, not everyone will want to have fluoride in drinking water without choosing. Simplistic carbon filters are not an easy solution for clearing away fluoride as carbon is inefficient in removing the substance. Implementing a complex filtration system is not an easy task, but it is a solution to at least reducing the amount of fluoride.

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