What Does a Berkey Water Filter Remove? Black vs. Phoenix

Berkey® gravity-fed systems have been tested for reducing a wide range of drinking-water contaminants, including chlorine and chloramines, lead and other tested metals, selected PFAS compounds, pesticides, volatile organic compounds (VOCs), and other substances.

But the answer to "What does a Berkey water filter remove?" depends on which filter element you're talking about. Black Berkey® Elements and Phoenix Gravity New Millennium Edition™ Filter Elements have different test histories, different service-life recommendations, and different certification status.

This guide compares the available evidence by contaminant category. Throughout the article, we use "reduce" as the default term because laboratory results reflect performance under defined test conditions and do not predict identical results under every household condition.

What Does a Berkey Water Filter Reduce?

Depending on the filter element and the specific laboratory report, published Berkey® testing includes results for contaminants and water-quality concerns such as:

• Chlorine
• Chloramines
• Lead
• Arsenic and other individually tested metals
• PFOA, PFOS, and other selected PFAS compounds
• Selected pesticides and herbicides
• Selected volatile organic compounds (VOCs)
• Selected disinfection byproducts
• Selected pharmaceutical compounds
• Selected petroleum-related compounds
• Selected radiological contaminants
• Taste and odor concerns covered by applicable testing or certification

Black Berkey® vs. Phoenix Gravity: Quick Comparison

The table is intentionally qualitative. A simple percentage-to-percentage comparison can be misleading because the Black Berkey® and Phoenix testing programs were performed at different times, by different laboratories, with different challenge concentrations, reporting limits, test volumes, and protocols.

For a broader product comparison, see Phoenix Gravity vs. Black Berkey® Elements: What's the Difference?

Does Berkey Reduce Chlorine and Chloramines?

Yes, published laboratory testing includes chlorine and chloramine reduction results for both Black Berkey® and Phoenix Gravity Elements.

Black Berkey®

Published Black Berkey® laboratory testing has evaluated free chlorine and chloramines under defined test conditions. Historical testing reported substantial reductions in both substances.

Because chlorine and chloramines can contribute to noticeable taste and odor, reducing them may change the taste and smell of filtered water.

Phoenix Gravity

Phoenix Gravity laboratory testing also reports substantial reductions in free chlorine and chloramines.

In addition to laboratory testing, Phoenix Gravity New Millennium Edition™ Filter Elements carry NSF/ANSI 42 certification for applicable aesthetic claims. Certain Berkey® system configurations using Phoenix Elements also have applicable system-level NSF/ANSI 42 listings.

The exact certified claims and configurations should always be read from the current NSF listing rather than assumed from laboratory reports.

Does Berkey Reduce Lead?

Published laboratory reports for both Black Berkey® and Phoenix Gravity Elements include lead-reduction testing.

Black Berkey® Lead Testing

Black Berkey® has historical independent laboratory documentation showing substantial lead reduction under the conditions of the applicable tests.

The Black Berkey® test library also contains results for other individually tested metals, including substances such as arsenic, chromium, copper, iron, mercury, nickel, selenium, and zinc.

Phoenix Gravity Lead Testing

Phoenix Gravity has newer independent laboratory testing for lead and numerous other metals. Published Phoenix documentation includes results for substances such as arsenic, cadmium, chromium, copper, iron, lead, mercury, nickel, selenium, zinc, and additional individually tested metals.

Does Berkey Reduce PFAS, PFOA and PFOS?

Published testing includes results for selected PFAS compounds, but PFAS should not be treated as a single contaminant.

PFOA, PFOS, PFBS, PFNA, PFHxS and other PFAS compounds are chemically distinct substances. A result for one compound should not automatically be applied to every member of the PFAS family.

Black Berkey® PFAS Testing

A historical Black Berkey® laboratory report directly challenged a filter with PFOA and reported substantial reduction under the test conditions.

The same documentation includes other fluorinated compounds, but some historical Black Berkey® results relied on PFOA as a surrogate. Those results should therefore be distinguished from direct testing of the individual compound.

Phoenix Gravity PFAS Testing

Phoenix has newer laboratory documentation involving direct testing of PFOA and PFOS at multiple service-volume checkpoints. Phoenix documentation also contains results for additional individually listed PFAS compounds.

When evaluating PFAS results, look at:

• The exact PFAS compound tested
• Whether the compound was tested directly
• The starting concentration
• The reporting or detection limit
• The amount of water processed before the sample was taken

Those details provide considerably more information than a broad statement such as "reduces PFAS."

Does Berkey Reduce Pesticides and Herbicides?

Published testing covers selected pesticides and herbicides, not every chemical in these categories.

Black Berkey® documentation includes results for compounds such as atrazine, alachlor, lindane, and simazine.

Phoenix Gravity documentation includes results for selected compounds such as 2,4-D, glyphosate, simazine, metolachlor, and trifluralin.

These results should be tied to the individual chemical and laboratory report rather than interpreted as evidence that every pesticide or herbicide has been evaluated.

Does Berkey Reduce VOCs?

Both Black Berkey® and Phoenix Gravity test libraries contain results for selected volatile organic compounds (VOCs).

Black Berkey® documentation includes testing involving compounds such as:

• Benzene
• Chloroform
• Toluene
• Trichloroethylene

Phoenix documentation includes results for selected VOCs such as:

• Benzene
• Chloroform
• Toluene
• Trichloroethene
• Vinyl chloride
• MTBE

Again, the correct interpretation is that these particular compounds were included in published testing. It should not be expanded into a claim covering every VOC.

For more information about one commonly discussed VOC, see our Benzene in Drinking Water guide.

What About Pharmaceuticals and Other Compounds?

The Black Berkey® and Phoenix test libraries extend beyond the categories above.

Depending on the specific laboratory report, testing has included selected pharmaceutical compounds, disinfection byproducts, petroleum-related compounds, radiological substances, and other individually identified contaminants.

Phoenix documentation, for example, includes laboratory results covering selected:

• Pharmaceutical compounds
• Disinfection byproducts
• Petroleum-related compounds
• Radiological substances
• Industrial chemicals
• Additional inorganic compounds

Rather than relying on a total number such as "200+" or "250+," we recommend checking the actual Berkey filter test results when a particular contaminant matters to you.

Does a Berkey Filter Reduce Fluoride?

Fluoride requires more explanation because Black Berkey®, Phoenix Gravity, and PF-2™ Elements should not be treated as equivalent products.

Black Berkey® and Fluoride

Historical Black Berkey® laboratory documentation includes a fluoride-reduction result under the conditions of the applicable test.

However, when customers want a component specifically designed for longer-term targeted fluoride reduction, Berkey® has traditionally used the separate PF-2™ Fluoride and Arsenic Reduction Elements.

Phoenix Gravity and Fluoride

Phoenix Gravity's primary element also has a published fluoride laboratory result. In an April 2026 test, fluoride decreased from approximately 8.0 mg/L to 1.96 mg/L, corresponding to an initial reduction of approximately 75.5% under those test conditions.

That result should not be interpreted as a sustained fluoride-reduction rating across the Phoenix element's entire service life. Manufacturer guidance specifically notes that the fluoride-reduction ability of carbon-based elements can decline relatively quickly.

PF-2™ Elements for Targeted Fluoride Reduction

Berkey PF-2™ Fluoride and Arsenic Reduction Elements are separate post-filter elements designed specifically for targeted fluoride and arsenic reduction.

PF-2™ Elements attach beneath compatible primary filter elements and are compatible with Phoenix Gravity Elements as well as applicable Black Berkey® configurations.

The PF-2™ Elements have their own preparation procedure, test history, service-life recommendation, and replacement schedule. They should therefore be evaluated separately from the primary Black Berkey® or Phoenix Gravity Element.

What Does a Berkey Filter NOT Remove?

No filter should be evaluated by assuming that anything absent from a contaminant list is automatically removed.

For Black Berkey® and Phoenix Gravity Elements, the safest way to evaluate performance is to ask whether there is specific evidence for the substance you care about.

There are also some important limitations to understand.

Berkey Filters Are Not Designed to Significantly Lower TDS

Neither Black Berkey® nor Phoenix Gravity Elements are designed to significantly lower Total Dissolved Solids (TDS). Unlike filtration methods intended to remove most dissolved minerals, these Berkey® filter elements leave naturally occurring dissolved minerals such as calcium and magnesium in the water.

For that reason, a TDS meter may show little difference between the water before and after filtration. This is normal and should not be interpreted as evidence that the filter is not working.

A TDS meter primarily measures dissolved ions in the water. It does not provide a direct measurement of many of the individual substances evaluated in Berkey® laboratory testing. Therefore, TDS readings should not be used as a general test of Black Berkey® or Phoenix Gravity filter performance.

For a detailed explanation, see Filtered Water and TDS Readings: What a TDS Meter Can and Cannot Tell You.

Phoenix Does Not Reduce Water Hardness

Phoenix Gravity Elements are not water softeners and are not designed to remove the dissolved mineral salts responsible for water hardness.

Water hardness and contaminant reduction are different issues.

Not Every Compound Has Been Individually Tested

A broad category such as "PFAS," "pesticides," "VOCs," or "heavy metals" can contain many individual substances. Published testing should not be expanded beyond the compounds actually evaluated.

Laboratory Testing Is Not the Same as NSF Certification

This distinction is essential when comparing Black Berkey® and Phoenix Gravity Elements.

Black Berkey®

Black Berkey® Elements have an extensive history of independent third-party laboratory testing covering many individually tested contaminants.

That testing should not be described as current NSF certification. A laboratory report using an NSF protocol or evaluating performance against criteria associated with an NSF standard is not the same thing as the product being currently certified and listed by NSF.

Phoenix Gravity

Phoenix Gravity New Millennium Edition™ Filter Elements have current NSF/ANSI 42 and NSF/ANSI/CAN 372 certification.

NSF/ANSI 42 addresses specified aesthetic effects and claims such as applicable chlorine, taste, odor, and particulate performance.

NSF/ANSI/CAN 372 addresses lead content in materials that contact drinking water. It should not be interpreted as a certification for removing lead already present in the water.

For a deeper explanation, see What Does NSF/ANSI 42 Certification Mean?

Why Black Berkey® and Phoenix Percentages Aren't Directly Comparable

A higher reported percentage does not necessarily mean one filter is better than the other.

The two testing programs differ in several important ways:

• Test dates — some Black Berkey® reports are considerably older than Phoenix testing.
• Laboratories — different labs may use different equipment and procedures.
• Challenge concentrations — filters may have been exposed to different starting concentrations.
• Reporting limits — one laboratory may be able to report lower concentrations than another.
• Test volume — an initial result is not the same as a result measured after hundreds or thousands of liters.
• Test protocols — the exact procedure may differ.
• Direct vs. surrogate testing — particularly important for some historical PFAS results.
• Component vs. system testing — an individual element and a complete system configuration are not necessarily the same test subject.

For that reason, we do not recommend selecting Black Berkey® or Phoenix Gravity Elements simply by finding the highest percentage in two unrelated laboratory reports.

How to Read a Berkey Filter Test Report

If a particular contaminant matters to you, look beyond the headline percentage.

Check these seven things:

1. Which exact filter element or system configuration was tested?
2. Which exact contaminant was tested?
3. Was the substance tested directly or evaluated using a surrogate?
4. What was the starting concentration?
5. What concentration remained after filtration?
6. At what service volume was the result measured?
7. Is the evidence an independent laboratory result or a certified claim?

A result reported as "below" a detection or reporting limit also deserves careful interpretation. It means the laboratory could not quantify the substance below that threshold; it does not necessarily mean the concentration was literally zero.

Black Berkey® or Phoenix: Which Has Better Contaminant-Reduction Evidence?

There isn't a useful single-number answer.

Black Berkey® Elements have a long history of independent laboratory reports covering a broad range of individually tested contaminants, including chlorine and chloramines, metals, PFAS, pesticides, VOCs, radiological substances, and other compounds.

Phoenix Gravity Elements has newer independent laboratory documentation across many contaminant categories and adds current NSF/ANSI 42 and NSF/ANSI/CAN 372 certification for the applicable claims.

Those differences mean each evidence set has strengths, but they should not be collapsed into a single "removes X%" comparison.

If you're choosing between the elements rather than researching one particular contaminant, see our complete Black Berkey® vs. Phoenix Gravity comparison.

Frequently Asked Questions

Check the Test Result for the Contaminant That Matters to You

The most useful answer to "What does Berkey remove?" is not a single contaminant count or percentage.

Instead, identify the contaminant you're concerned about and check:

• The exact filter element tested
• The laboratory report
• The starting and final concentrations
• The test volume
• Whether the contaminant was directly tested
• Whether the claim comes from laboratory testing or certification