Water Filter vs. Water Purifier

The term water filter is universally used to describe many water filtration devices including the Berkey systems. While the term can be an accurate description, the meaning when talking about water treatment standards is different.

So, What is the difference between a water filter and a water purifier (Berkey)?

  Protozoa Bacteria Viruses

Water Purifier

✔️ ✔️ ✔️

Water Filter

✔️ ✔️

Water filters remove waterborne protozoa and bacteria, but not viruses. Water purifiers filter out protozoa, bacteria and viruses. Let's take a look at the two standards when classifying water treatment devices:

Water Flowing Through a Filter Viewing Purified Water Through a Microscope

Water Purifier

In order to be in this classification the following standard must be met:

Contaminant Species Removal Standard Berkey Removal %
Pathogenic Bacteria Klebsiella Terrigena >99.9999% (6-log)
99.9999999% (9-log)
Virus Polio and Rota >99.99% (4-log) 99.99% (4-log)


All Berkey systems contain the Black Berkey Filters and meet the Water purifier standard. In fact, Berkey water purifiers far surpass this standard and actually remove 99.9999999% known as a (9-log reduction), when dealing with pathogenic bacteria.

Berkey purifiers also reduce viruses by 99.99% (4-log reduction). This distinction is what makes Berkey the only certifiable gravity flow water purification system on the market.

Water Filter

This classification must meet the following standard:



Removal Standard

Pathogenic Bacteria Klebsiella Terrigena >99% (4-log)


To see how Berkey stacks up against other brands, head over to Berkey vs. The Competition. Take note that some use harsh chemicals, like iodine or chlorinating tablets, in order to reach the level of purification. We do not have to use chemicals in our unique ionic adsorption process mated with simple microfiltration. In short, these two methods create a pore structure so minute that contaminants are removed from the water because they simply cannot pass through the charged filtering media.

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