Big Berkey BK4X2 Countertop Water Filter Review [Staff Tested]

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Written by Leigh Matthews, BA Hons, H.Dip. NT


Leigh Matthews, BA Hons, H.Dip. NT

Sustainability Expert

Leigh Matthews is a sustainability expert and long time vegan. Her work on solar policy has been published in Canada's National Observer.


The Big Berkey is a popular countertop water filter, but does it live up to the hyper? Here’s our first hand review, based on personal experience, with some things to consider before choosing this model.

Big Berkey Water Filter [Staff tested]

Leaf Score

Highlights: Attractive, portable, gravity-fed water filter system that doesn’t need power. Lacks third-party certifications though, and very expensive.

Table of Contents
  1. Big Berkey Water Filter [Staff tested]
  2. Overview
  3. We tested the Big Berkey
  4. Berkey filtration capacity
  5. Warranty and filter changes
  6. Why choose the Big Berkey and black filters?
  7. Berkey vs. Aquasana AQ-4000 vs. ZeroWater vs. Brita
  8. Big Berkey Water Filter [Staff tested]

What we like

  • Ease of setup
  • Conversation piece
  • Portable

What could be better

  • No NSF certification
  • Filters can be very slow and leave behind a constant pool of water in the upper chamber
  • Fluoride filters make the product so slow as to be almost unusable


With a Leaf Score of just 1, you might wonder why the Big Berkey with Black filters is included in the Leaf Score directory. This is because it is massively popular and may well be one of the best activated carbon filter system available. The problem is, it’s difficult to tell how good this filter really is, given the lack of NSF certifications and the lack of transparency from the company. If the company steps up its game and gets at least one product certified, that Leaf Score (and our respect) would certainly increase.

On its face, the Berkey system appears to be robust and portable, with self-sterilizing and cleanable elements with micro-pores small enough to stop pathogenic bacteria from passing through. It is said to remove 99.999999% of contaminants but to retain essential minerals, so your water tastes great but isn’t stripped of elements you actually want to consume. And it does all this while looking fantastic.


  • A lack of NSF certifications and transparency makes it difficult to tell how good the filter really is
  • According to what the product states it does, it’s more of a water purification system than a filtration system
  • Independent testing has found that the Black filters were poor at filtering chloroform (only a 13% decrease) despite the company’s claim of nearly 100%.

We tested the Big Berkey

Some readers who are loyal to the Berkey brand have been upset at our skeptical review. We still use our old Berkey on occasion and appreciate the simplicity of setup. However, when we have tested the filters using TSD measuring sticks, the Berkey doesn’t add much value over tap water. Of course, the TSD at-home tests are not the end all be all, but it’s just one more reason we would like to see more data on the Berkey’s capabilities.

Berkey filtration capacity

If Berkey’s claims are true, the Berkey is, technically, a water purification system rather than a filtration system. And, because it is a gravity filtration system, it doesn’t require any power, making it potentially ideal for taking camping or traveling, and for use in rural areas or during natural disasters. It’s also become a popular water filter for survivalists for the same reasons and because the Berkey Black filters are said to be able to process up to 3,000 gallons of water.

So, you might not need to change these filters for at least eleven years, making this an eco-friendly and durable water filtration system indeed. The fluoride filters can filter up to 1,000 gallons each. Independent testing has also found that the Black filters are exceptionally good at filtering out lead.

However, the same independent testing found that the Black filters were poor at filtering chloroform, noting only a 13% decrease compared to the company’s claim of almost 100%. And, interestingly, Berkey filters seem to share the same filtration mechanisms as many other filters, namely activated charcoal impregnated with an ion-exchange resin. The company claims that their filters have ‘at least’ six different filter technologies, however, but doesn’t state what these are.

Downsides to Berkey

Because Berkey refuse to get their products certified to NSF standards, it is difficult if not impossible to compare the Berkey to other water filters.

Some other concerns over this company and product include:

No shipping to California

Because Berkey doesn’t ship its products to California, this could suggest they are not in adherence with Prop 65 and may contain lead or other heavy metal.

Doesn’t work for all pHs

The Berkey fluoride filters only work at the stated level of efficiency for water with a pH of 5-7, ideally closer to 5 (which is acidic, so, it’s unlikely your water is this pH naturally). If your water is not within that range, the Berkey fluoride filters will still work, just less effectively.

If you are considering buying a Berkey system to filter fluoride, test your water pH first. You can do this through your local health department or get test strips at a pharmacy.

Can make water taste like rubber

If you don’t use all four filter connections and instead use the rubber plugs to seal the holes, you may end up with water that tastes like rubber. The design of the Berkey means that water does not fully drain from the top, with around an inch of water sitting around the plugs at any given time.

Cleaning the plugs in warm, soapy water every few days can help, but it’s probably best to replace the plugs and washers with silicon versions instead. Or, use four filters, which also helps fill the tank faster.

Needs cleaning monthly

To keep the Big Berkey free from rust and other issues, it’s best to clean it once a month with soap and water. And, if it starts filtering slowly after a few months, re-prime the filters.

Poor customer service

Be careful where you buy from. If you need to send back parts or all of your filter system, Berkey does not seem very willing to accept returns even if you bought from it directly.

Warranty and filter changes

New Millennium Concepts, Ltd. (makers of the Berkey Systems) Warrants this product to be free from defects in materials and workmanship for a period of 6 months from date of purchase. Black Berkey purification elements have a two-year prorated warranty calculated in six months intervals. In reality, many customers have complained about poor response times and refusals to replace or refund malfunctioning products.

Why choose the Big Berkey and black filters?

If the Berkey still seems good to you, the Big Berkey with Black filters is likely the best of the bunch. It includes stainless steel housing (Upper, Lower, Lid and spigot), 2 Black Berkey Filters, and 2 Fluoride Elements. The Big Berkey holds 2.25 gallons of purified water and is ideal for home use for 4 to 16 people. The Big Berkey is made with grade 304 stainless steel and measures 8.5″D x 21″H when assembled. The upper chamber nests within the lower chamber for transport and stands only 13″ in height.

This model can accommodate up to four Berkey Purification elements and four Fluoride filters, however, only two of each are included with this package. Configured with four Black Berkey purification elements the system will purify up to 7 gallons (13.3 liters) per hour.

It’s a good idea to include the glass sight spigot (View Price on Amazon) if buying a Big Berkey as this makes it much easier to see the water level in the tank, rather than having to lift the top half and peer inside. Before filling the top chamber, it is best to wait until all the water is gone from the bottom.

Berkey vs. Aquasana AQ-4000 vs. ZeroWater vs. Brita

The Berkey is an attractive option that fits into most modern and classic kitchens, but its looks and portability may be all it has going for it. If those are your main considerations, ZeroWater’s 40-cup dispenser is just as attractive, however. This dispenser is made of glass and steel (for the most part), and is also certified to NSF Standard 53, unlike Berkey.

If serious filtration is what you’re after from a countertop unit, though, go for the Aquasana AQ-4000, which carries a range of excellent certifications for filtering out far more than either the Berkey or ZeroWater, although it isn’t as portable because this one has to be hooked up your faucet.

Big Berkey Water Filter [Staff tested]

Leaf Score

Highlights: Attractive, portable, gravity-fed water filter system that doesn’t need power. Lacks third-party certifications though, and very expensive.

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  1. Regretting my just placed order 🥴😭 thank you very much for your review.
    I just saw another review doubting Berkey’s pesticide capacity 😭 I feel I just made worst decision ever!
    Why don’t just hace one black filter certified with give peace of mind…

    • Ana,

      Thanks for the comment. Berkey is still a decent option, definitely not the worst decision ever! Having said that, they could definitely be doing a lot more to “show the math” and to prove that their filters are as efficient as they claim to be.

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