Do Berkey Water Filters Remove Fluoride?

Berkey water filtration systems can reduce fluoride from drinking water, but only when paired with the optional PF-2 Fluoride and Arsenic Reduction Filters. Neither Black Berkey Elements nor Phoenix Filter Elements are engineered for sustained long-term fluoride reduction on their own. The PF-2 add-on attaches directly to either filter element in the lower chamber and is rated for 1,000 gallons per set before replacement.

If fluoride is your primary concern, the right setup is your choice of Black Berkey Elements or Phoenix Filter Elements in the upper chamber, plus PF-2 filters in the lower chamber. Both configurations deliver wide-spectrum contaminant reduction in stage one, followed by targeted fluoride and arsenic reduction from the PF-2 stage.

Is the PF-2 Add-On Right for You?

Why Fluoride in Drinking Water Is a Concern

Water fluoridation is the practice of adding fluoride to public drinking water to reduce tooth decay. The CDC and EPA set the current recommended limit at 0.7 mg/L, while the enforceable Maximum Contaminant Level (MCL) is 4.0 mg/L. Many municipal systems operate well below the MCL, but long-term cumulative exposure at even moderate levels is a growing subject of research.

A published study in the scientific literature linked high fluoride exposure in drinking water to dental fluorosis, skeletal fluorosis, joint problems, and potential effects on the endocrine and neurological systems. Research has also examined prenatal fluoride exposure and developmental outcomes in children, which is why many families with infants or those who are pregnant are particularly motivated to reduce fluoride in their drinking water.

You can find the fluoride level for your water supply in your municipality's annual Consumer Confidence Report (CCR), typically available on your water utility's website.

Why Berkey Filter Elements Alone Are Not Enough for Long-Term Fluoride Reduction

Black Berkey Elements use a proprietary blend of more than six filter media types operating through four mechanisms: microfiltration via a tortuous path pore structure, adsorption, absorption, and ion exchange. Phoenix Filter Elements use a CTC-60 coconut shell GAC solid carbon block with nanofiber composite. Both configurations are tested against 200+ contaminants, including heavy metals, pharmaceuticals, VOCs, pesticides, PFAS, and radiologicals.

Fluoride, however, requires a different approach regardless of which element you use. Fluoride ions are small and highly soluble, which means they pass through most filtration media without being fully captured. Both Black Berkey and Phoenix Elements can reduce fluoride to a degree in the short term, but neither is optimized for sustained fluoride reduction over the life of the filter. As the filter ages and media sites become occupied with other contaminants, fluoride reduction performance drops.

The PF-2 filter solves this by using activated alumina as its primary medium. Activated alumina is widely regarded as the most effective media available for fluoride and arsenic reduction in drinking water, which is why it is used in municipal water treatment systems and approved by the NSF for point-of-use fluoride reduction. It works through adsorption: fluoride ions bond to the surface of the alumina granules as water passes through, and stay there rather than passing into your glass.

A common question is whether activated alumina introduces aluminum into the filtered water. It does not. Activated alumina is a food-safe, FDA-recognized material with a stable crystalline structure. Unlike soluble aluminum compounds, it does not dissolve into water under normal filtration conditions. The same material is used in pharmaceutical applications and food processing. If you want the full technical breakdown, we cover it in detail in our article on whether Berkey systems leach aluminum into drinking water.

Activated alumina maintains its fluoride-reduction affinity consistently across its rated life of 1,000 gallons per set. Because the water passes through either Black Berkey or Phoenix Elements first, the PF-2 receives water that has already had the heavy contaminant load reduced, protecting the alumina media and allowing it to focus on what it is designed to do.

How the Two-Stage Fluoride Reduction Process Works

1. 1
   Upper Chamber: Black Berkey or Phoenix Filter Elements Water is poured into the upper chamber and gravity-feeds through your filter elements. Black Berkey Elements use a six-plus media blend across four mechanisms. Phoenix Filter Elements use a solid carbon block with nanofiber composite. Both reduce PFAS compounds, heavy metals, chlorine, chloramines, pharmaceuticals, pesticides, VOCs, radiologicals, and a broad range of additional contaminants tested across 200+ parameters. Water exits through the element stem into the lower chamber.
2. 2
   Lower Chamber: PF-2 Fluoride Filters The pre-filtered water then flows through PF-2 filters, which thread onto the bottom of the filter elements and hang into the lower chamber. This works the same way whether your system uses Black Berkey Elements or Phoenix Filter Elements. The activated alumina media adsorbs fluoride and arsenic ions as the water passes through. Filtered water collects in the lower chamber and is dispensed through the spigot.

PF-2 Filter Quick Specs

Getting the Most Out of Your PF-2 Fluoride Filters

PF-2 filters have a rated life of 1,000 gallons per set. For a household of four using a 2.25-gallon Berkey system and consuming approximately 1 gallon of filtered water per day, that translates to roughly 3 years of service per set. Larger families using larger systems (Royal Berkey, Imperial, Crown) will cycle through PF-2 sets more quickly, so track usage accordingly.

Because your main filter elements, whether Black Berkey or Phoenix, reduce the bulk of the contaminant load before water reaches the PF-2 filters, the PF-2 media stays cleaner than it would in a single-stage system. This means PF-2 filters rarely become blocked during their rated lifespan. If filtration slows noticeably, the issue is almost always the main filter elements, not the PF-2 filters. Clean those first before suspecting the PF-2 stage.

PF-2 filters can be refreshed by rinsing them under running water if any sediment accumulates on the exterior, but the activated alumina media inside does not require scrubbing. Replace the set after 1,000 gallons or annually, regardless of visual condition, because the activated alumina becomes saturated with fluoride ions even when it looks clean from the outside.

For full contaminant reduction data across all Berkey filter configurations, see our downloadable lab test results. Independent media coverage of Berkey's filtration performance, including PFAS testing covered by EWG and CBS News, is documented on our media coverage page.

Do Berkey Filters Reduce Fluoride? Frequently Asked Questions