how to remove fluoride from water for free

Processes such as reverse osmosis or distillation and compounds such as activated alumina or bone char are effective means to removing fluoride from drinking water.

Because fluoride ions are microscopic in size, standard carbon filtration will be ineffective in removing fluoride from water. Therefore, fluoride ions must be addressed at the molecular level in order for effective removal to take place.

Reverse Osmosis

One of the most effective and most practical methods for removing fluoride from a home water supply is to install a reverse osmosis system.

Reverse Osmosis works by using pressure to force water through a permeable membrane which only allows water molecules to pass through. The end result is a concentration of water that is absent of any molecule other than H20. All other contaminants, minerals, and ions are unable to pass through the membrane.

reverse osmosis colored diagram

Because water that has been treated through reverse osmosis lacks any minerals, the water can have a slightly lower pH and can taste flat. Many RO systems include remineralization filters which add minerals back into the water, raising the pH levels and improving the taste.

RO systems can be installed under the kitchen sink which treats the water just before it exits the faucet or installed as a whole house system. This article reviews the most practical reverse osmosis systems for home use.

Activated Alumina

Activated alumina, better known as aluminum oxide, is a compound found in sapphires and rubies but without the impurities that give these gemstones their distinct color. With its high surface-area-to-weight ratio, activated alumina has a very high capacity to absorb fluoride and is recommended by the EPA as an effective medium in removing fluoride, arsenic, and thallium.

Activated Alumina

GOKLuLe / Wiki Commons

In order for activated alumina to be effective, the water must have pH of 6.5 or lower and for proper absorption to occur.

While many fluoride filters use activated alumina as their primary medium for fluoride removal, it is important to note that activated doesn't remove 100% of fluoride from water but reduces it to a much safer concentration – around 0.1 ppm.

Bone Char Carbon / Brimac Char

Bone Char, also known as Brimac Char, is one of the oldest methods for fluoride removal in the United States. Made from finely crushed cattle bones which are heated, bone char has a very high absorption capacity for fluoride and many other contaminants including lead, arsenic, and cadmium.

Bone Char

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Like activated alumina, bone char has a very porous ionic surface, making it extremely efficient in absorbing both inorganic and organic materials, especially fluoride. Also like activated alumina, bone char filtration works best at a slightly acidic pH level and a lower flow rate to ensure better absorption.

Bone char comes in the form of filter cartridges and will remove fluoride up to 90% of fluoride depending on the quality of the bone char and the frequency at which the filters are replaced.

Bone char, along with activated alumina and reverse osmosis, is one of the 3 methods the EPA considers to be the most effective ways to remove fluoride from water.

Distillation

The oldest, least expensive method for purifying water is through distillation. Like the earth's hydrologic cycle, distillation works through the natural processes of evaporation and condensation.

Solar still diagram

As fluoride-concentrated water is heated, steam evaporates from the boiling water and condenses onto a surface. The condensation collects into a new container, leaving the fluoride and other contaminants behind. The end result is pure, distilled H20.

Like reverse osmosis, the process of distillation removes more than just fluoride but particles and ions altogether, leaving the water empty of minerals and slightly acidic. Remineralization is advised in order to raise the pH level and improve the quality of taste.

Home countertop distillation units can be purchased for convenient distilling whenever needed. Because of the relatively slow rate at which water is distilled, distillation units are more practical for individuals or small families. This article reviews the best countertop water distillers for home use.