What is a Berkey Water Filter?

Heard the rave reviews about the Berkey, but not exactly sure what it is or how it works? You’re in the right spot, this is Berkey 101. We’ll explain what the Berkey is, and how it works. 

Simply put, the Berkey water filter is an ultra effective freestanding water purification system; designed to sit on your kitchen counter. You can pour water from almost any source into the upper chamber of the unit, and open the tap on the lower chamber to dispense the purest, healthiest water you can get.

That is the Berkey in a nutshell. Now let’s look more in-depth at the details of this exceptional water purification system.

How Berkey Filters Work.

The Black Berkey purification elements work on three different principles: absorption, adsorption, and microfiltration. Let's look at these principles one at a time.


This is the part of the purification process that Berkey filters have in common with the legacy filters like the old Royal Doulton or the British Berkefeld. The microscopic topography of the surface of the filter elements contains millions of tiny holes that let water pass through. These holes are so minute that they strain out even tiny bacteria. Furthermore, these micropores pass through the filter shell in convoluted twists and turns known as a “tortuous path,” further ensnaring the tiniest of single-celled organisms; 99.9999% of them, to be exact!

Unfortunately, in modern times, we have more contaminants to deal with than germs alone. Agricultural and industrial activity can contaminate the water with pollutants like heavy metals and volatile chemicals that require more than just microfiltration.

How does a berkey work


For contaminants like heavy metals, which are too small to be removed by simple filtration, Berkey employs the principle of absorption. Absorbing chromium, lead, or copper into a filter is a lot like what you do when you absorb funny smells from your refrigerator by leaving out an open box of baking soda. The contaminants get drawn into the filter elements and never come out again. They do this by the principle of ion exchange, so that negative heavy metal ions are permanently bonded to the media and cannot leave or be washed away.


Viruses are tricky. If you remember from high school biology class, they are technically not even alive, primarily because they are not made of cells. If they were, they could be filtered out by microfiltration. What they are is short little strips of DNA or RNA, drifting around with just enough genetic information on them so that when they passively bump into living cells, they get stuck to them, hack into their control systems, and trick them into becoming virus factories. These nasty little guys are much too small to be filtered out and they can’t be absorbed into filter media. 

This is where Berkey filters really shine. Our filters take advantage of their electrostatic charge and pull them in against the walls of the tunnels in the “tortuous path” mentioned above. This is what we refer to as adsorption. Picture static cling. It holds tiny viruses against the surfaces in the filter and never lets go.

How Well do Berkey Filters Work

The results of independent lab testing of the Berkey permit it to be qualified as a water purifier as opposed to just a water filter. To be called a water filter, a product must remove pathogenic bacteria to a level of 99.99%. The higher standard of water purifier requires a removal of 99.9999% of pathogenic bacteria.

Independent test results show that Berkey meets NSF/ANSI standard 53 for reductions in heavy metals, like mercury and lead, disinfectant byproducts, parasites like Cryptosporidium and Giardia, VOCs like dichlorobenzene, trichloroethylene, and MTBE as well as radon and pesticides.

That isn’t all the Black Berkey can do. Our water purifiers remove chlorine to undetectable levels and industrial carcinogens like trihalomethane and perfluorochemicals to greater than 99.9%. They also remove pharmaceutical contaminants, BPA, petroleum contaminants, and heavy metals to greater than 99.9%.

Does Berkey Remove
Chromium 6?

While most water filters don’t remove chromium-6, the good news is Berkey filters remove >99.8% of Chromium-6.

Does Berkey Remove Minerals?

Learn more about beneficial minerals in your water.

Do Berkey Filters Change Your pH Level

Depending on your water, Berkey may change the pH level