Clearly Filtered vs Berkey (An Objective, Data-Driven Analysis & Comparison)

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Clearly Filtered and Berkey are two gravity-fed water filter brands that are well-known for their ability to reduce hundreds of contaminants in drinking water.

We recently had the opportunity to extensively test the Big Berkey system and the Clearly Filtered pitcher ourselves, comparing them across a variety of data-driven performance factors, and we’ve shared everything you need to know in this review.

In our testing, Berkey and Clearly Filtered performed differently, and each had their own advantages and setbacks.

We found that the two systems did a great job of reducing our water’s contaminants, but Clearly Filtered has the advantage of an official performance certification. Both filters produced some unexpected outcomes: the Berkey fluoride filters leached aluminum oxide, and cobalt appeared in our water after filtering it through the CF pitcher.  

📊 Our Testing Data

At Water Filter Guru, we test water filters across a series of 6 performance categories. We awarded the following scores to Berkey and Clearly Filtered:

FactorClearly FilteredBig Berkey
Contaminant Reduction8.248.85
Filtration Rate10.0010.00

If you want to know the nitty-gritty, we’ve shared exactly how we reached the scores for both systems in the table below.

FactorClearly FilteredBig BerkeyWinner
Overall Score8.788.60Clearly Filtered
Health Related Contaminants8.309.30Big Berkey
Aesthetic Related Contaminants9.906.70Clearly Filtered
Performance CertificationNSF/ANSI 42 & 53NoneClearly Filtered
Filtration Rate2.27 GPH2.60 GPHBig Berkey
Component QualityOutstandingExcellentClearly Filtered
Component CertificationNSF/ANSI 42, 53 & 372NoneClearly Filtered
SetupOutstandingFailingClearly Filtered
Servicing RequirementsOutstandingWeakClearly Filtered
Costs$0.55/ gal$0.13/ galBig Berkey
Warranty Length2 yearsLifetimeBig Berkey
ShippingFree shipping to all states$99 order thresholdClearly Filtered
Returns30 days30 daysTie

🚰 Contaminant Reduction

Starting with the most important testing category, we compared the Clearly Filtered pitcher and Big Berkey system’s contaminant reduction performances. To do this, we combined the data from our own water quality testing with evidence of official performance certifications from the WQA, NSF, or IAPMO.

Our Lab Test Results

We used Tap Score by SimpleLab to test our water quality before and after filtering it through each water filter system.

water testing with tap score

Tap Score has produced its own Health Guideline Levels (HGLs), which are stricter than federal legal limits for contaminants in drinking water. We used the HGLs to determine the safety of our water based on the contaminants detected.

Good to Know: We tested the Berkey and Clearly Filtered systems on separate occasions, with two separate water supplies. Different contaminants were detected in each water supply, so we can’t compare the two filters directly for their contaminant reduction. However, we still think it’s interesting to see which contaminants each system could reduce.

Below, we’ve listed the contaminants detected in our water, how they compared in our water filtered by Clearly Filtered and Berkey.

ContaminantMeasurementUnfiltered WaterClearly Filtered% ChangeUnfiltered WaterBerkey Test 1% ChangeUnfiltered WaterBerkey Test 2% Change
Total ColiformsCFU/100mLNDNDND150-100%NDNDND
Total THMsPPBNDNDND27.040-100%35.20-100%

Both filters impressed us with their performances here, but Berkey’s score was pulled down by a negative outcome we experienced with our initial test. We ended up testing the Big Berkey system twice, and we’ve combined and averaged the scores from both tests to reach its overall score.

Health-Related Contaminants

We started by comparing the systems for their ability to reduce health-related contaminants in our water. 

When we tested the Big Berkey, Berkey said that it could be used to filter treated water and untreated water*, like river water or lake water. So, we tested it first with our treated city water, and then another time with untreated river water.

*Berkey has since revoked these claims. 

The Clearly Filtered pitcher can only be used with treated water, so we conducted just one test, using treated groundwater.

Treated Water Testing

The water we tested in the Clearly Filtered pitcher contained 8 health-related contaminants, including fluoride, uranium (both present above the HGL), nitrate, and barium.

The full list of contaminants detected in our test can be found in the table below.

Nitrate (as N)PPM3.510
Total Dissolved SolidsPPM137none

Our filtered water test results showed that the Clearly Filtered pitcher had done a great job of reducing 100% of fluoride and uranium, the contaminants we were the most concerned about. It also reduced 100% copper, 86% barium, 67% strontium, and 53% molybdenum. It did a poorer job of reducing just 11% nitrate and 3% sulfate.

The only unusual outcome of our test was that cobalt, which hadn’t been detected in our unfiltered water test, had increased to 0.0054 PPM in our filtered water. This was unexpected, especially since the filter has been third-party tested to reduce cobalt by >98.31%. We don’t know for certain why this happened, and we plan to retest the pitcher to see if this was a one-time anomaly or a possible issue with the filter.   

The water we filtered in the Big Berkey system contained 12 contaminants with potential health effects, including lead, chloroform, total THMs, bromodichloromethane, and cobalt, all of which were detected at concentrations that exceeded the Tap Score HGL.

ContaminantMeasurementDetection Test 1Detection Test 2HGL
ChloroformPPB23 35.2 0.22
Total THMsPPB27.0435.2 0.32
FluoridePPM0.20.1 0.8

The Berkey filter eliminated 100% of all three disinfection byproducts detected in our water, as well as 100% copper, barium, and manganese. Additionally, it reduced 3.23% of cobalt. So far, so good.

But there was one outcome of our testing that we were very concerned about. The concentrations of aluminum in our water had increased to 1.4 PPM after it had been filtered through the Big Berkey system, greatly exceeding the HGL of 0.6 PPM. After talking with the testing lab, we think the Berkey fluoride filter’s alumina filtration media had leached aluminum oxide into our water.

We were also disappointed to see that fluoride was only reduced by 50%, while Berkey claims that the fluoride filters reduce up to 99.99% of this contaminant.

We wanted to know whether this outcome was normal or a one-off issue, so we retested our water with a brand-new set of fluoride filters. This time, we ran more than 100 gallons of water through the filters before we conducted our test. And good news: 100% of fluoride was reduced in our water, and aluminum levels only increased slightly from 0.052 PPM to 0.069 PPM.

The concentrations of sodium and potassium had also increased in our filtered water, but we experienced a similar anomaly with many of the gravity water filters that we tested at the same time. We think this was caused by the presence of these impurities in the initial 100 gallons of water that we filtered through the system, which was different from our test water.

Untreated Water Testing

In our untreated water test, our priority was to make the water potable by reducing microorganisms. Total coliform was detected in our unfiltered river water, and our test results showed that the Big Berkey system reduced 100% of this bacteria, so our water was microbiologically safe to drink.

However, since Berkey has now revoked its claims to filter untreated water, we wouldn’t recommend using the Big Berkey system with untreated water. 

Aesthetic Contaminants

Both of our treated water sources had been disinfected with chlorine. Around 1 PPM of chlorine was detected in our Clearly Filtered test water, and around 0.5 PPM was detected in our Berkey test water.

Both filters reduced 100% of this chemical, and we could no longer detect any chlorine tastes or odors in our filtered water supplies.

Clearly Filtered Pitcher chlorine test

Performance Certifications

Performance certifications give us reliable evidence of a filter’s contaminant reduction abilities. Only one of the two systems we compared in this review has been certified.

The Clearly Filtered pitcher has a WQA certification to NSF/ANSI Standard 42 and Standard 53, for its ability to reduce chlorine, PFOS, and PFOA. That’s good to see, but we wish the pitcher was certified to remove even more contaminants, like lead, chromium-6, and VOCs – especially since the filter has been third-party tested to reduce 365 contaminants.

The Big Berkey is only third-party tested for its contaminant reduction performance, so we don’t get the same reassurance of an official certification.

🚦Filtration Rate

We measured Berkey and Clearly Filtered’s filtration rate in gallons per hour (GPH), and you can compare their performance in the table below.

ProductFiltration Rate ScoreFiltration Rate
Clearly Filtered10.002.27 GPH
Big Berkey10.002.60 GPH

The Clearly Filtered pitcher filtered 0.5 gallons of water in 13 minutes and 12 seconds, giving it a filtration rate of 2.27 GPH.

The Big Berkey’s filtration rate was only slightly faster, at 2.6 GPH. We actually thought Berkey would have a much quicker rate of filtration because it uses two Black Berkey elements, which are larger than Clearly Filtered’s cartridges.

However, we tested the Berkey filters after passing a lot of water through them, while the CF filter was still relatively new when we tested it, which could explain the difference in filtering speed.

💲 Upfront Cost

Clearly Filtered is expensive compared to most other water filter pitchers we’ve tested, but the Big Berkey unit is even more expensive.

When we got the Clearly Filtered pitcher, it cost $90. We could get a discount on the pitcher if we signed up for Clearly Filtered’s replacement filter subscription service.

The Big Berkey costs $447.00, which is one of the highest prices we’ve come across for a stainless steel gravity-fed filter. This price includes two initial Black Berkey filter elements, but a pair of fluoride filters costs an extra $99.99. That brings the total cost up to $546.99.

In terms of value for money, our take is that Clearly Filtered is best. Given that both filters perform very similarly, we don’t understand why Berkey is so expensive – even with its larger water-holding capacity and longer filter lifespan.

We think Clearly Filtered is the best option if you have a smaller budget but still want to reduce a lot of contaminants, while Berkey is the better choice for bigger budgets.

ProductInitial PriceFilters IncludedReplacement Filter Cost
Clearly Filtered$90.001$49.50
Big Berkey$447.002$99.99

📐 Design

Performances aside, we wanted to know how Berkey and Clearly Filtered compared on the design front.

They have their obvious differences: the Big Berkey is a stainless steel system and is much larger, holding 2.25 gallons of water, while the Clearly Filtered pitcher holds just 10 cups. 

But what did we think about the filters’ design quality and durability? And did we find any materials safety certifications for any of the systems?

We’ve shared our results for both systems in the next table.

ProductDesign ScoreComponent QualityMaterials Safety
Clearly Filtered9.70OutstandingCertified
Big Berkey7.80ExcellentNot certified

The two systems had their pros and cons in this category, but Clearly Filtered got the better score because it has a certification for materials safety. 

Filter Models

Berkey sells a range of countertop water filters that can be used with its Black Berkey elements and fluoride filters, while Clearly Filtered currently only sells a single pitcher model/size: the 10-Cup Water Filter Pitcher.

Clearly filtered pitcher parts

Here are the countertop filtration systems that Berkey currently offers: 

Most Berkey systems are made from stainless steel, apart from the Berkey Light (this system is made from BPA-free plastic and is a bit cheaper than the other units).

unboxing big berkey

You might not have a preference for water-holding capacity, but it’s something that’s worth considering. We think Clearly Filtered is the better option if you prefer a portable water filter pitcher that you can easily carry from room to room and take with you on your travels. Berkey is better if you like having the choice between different unit sizes and you prefer a larger unit that holds more water.  

Component Quality 

In terms of component quality, Berkey and Clearly Filtered are pretty different.

The Big Berkey’s water chambers are made from stainless steel, so the system should appeal to anyone who’s concerned about microplastics leaching.

But some elements of the unit are still made from plastic, including the spigot and the filter molds.  

Still, we were pleased with the feel, functionality, and overall design quality of the Berkey system. We thought the steel felt sturdy and durable, and we didn’t experience any rusting during our testing.

The Clearly Filtered pitcher is made of Tritan plastic, which puts it at a disadvantage for folks who want to limit their exposure to plastics where possible.

But plastic has a few design advantages as well, including its affordability (likely one of the reasons why the CF pitcher is so much cheaper than the Big Berkey), its heat resistance, and its lightweight feel.

We also thought that the Clearly Filtered pitcher’s materials felt sturdier and better quality than most of the other water filter pitchers we’ve tested.

Filter Materials

Both Clearly Filtered and Berkey use advanced filtration media, which explains why they’ve each been tested to reduce hundreds of contaminants.

The filters used in the Clearly Filtered pitcher contain activated carbon block media, a composite shell, and a woven stainless steel mesh screen. There are also a few “proprietary materials”, which Clearly Filtered hasn’t disclosed. We think these media could include ion exchange resin and KDF media, based on the contaminants that the filter can reduce. 

Holding a Clearly Filtered water filter pitcher replacement cartridge

The Black Berkey elements are also activated carbon filters, and Berkey has revealed that the filters use ion exchange resin. But, like Clearly Filtered, Berkey has chosen to keep its other filtration materials under wraps. 

Unboxing new black berkey filter elements

Berkey’s PF2 fluoride filters are made from activated alumina, which we’ve seen used by several water filter manufacturers, favored for its ability to reduce fluoride and arsenic. This media is generally safe and shouldn’t cause leaching, but we did experience leaching with Berkey (there’s a chance that our initial filters were faulty). There’s also risk of user error causing the leaching if you over-tighten the PF2 filters

Berkey PF2 fluoride filters next to filter system

Materials Safety Certification

Only Clearly Filtered has obtained a materials safety certification as a component of its performance certifications. The pitcher is also WQA certified to NSF Standard 372 for lead-free design.The Big Berkey unit has no materials safety certification. This prevents Berkey units from being sold in California.

⚙️ Setup

We timed the setup process for Berkey and Clearly Filtered, and there was an obvious winner out of the two. 

Here are our setup times and scores for both systems. 

ProductSetup ScoreSetup Time
Clearly Filtered9.50Around 10 minutes
Big Berkey6.50Around 20 minutes

The Clearly Filtered pitcher was the quickest system to set up by a mile. We just washed and assembled the pitcher (which was easy because it only has three main components: the pitcher, the upper reservoir, and the filter). Our pitcher came with a priming bag, and it took 10 minutes to prime the filter. 

The Berkey unit was also quick to assemble, although it uses more parts, and the process took around 20 minutes. 

It was the filter priming process that took the longest for Berkey. Again, the unit came with a priming tool, but we found it difficult and time-consuming to use. We found it almost impossible to get a seal with the tan priming washer on our faucet, and priming the filters took over an hour. 

Some Berkey distributors also sell a blue priming nipple, but it only fits older faucets.

Note: Neither Berkey priming method is suitable for a spray or pullout faucet.

We also washed out the Berkey water chambers before we used them, which was a little trickier than the Clearly Filtered pitcher because the chambers didn’t fit in our kitchen sink. 

You might be looking specifically at countertop water filtration systems because they don’t need a permanent install, but keep in mind that Berkey’s setup process is quite complex and time-consuming. 

We recommend Clearly Filtered to folks who want to be able to quickly and easily set up their filtration system for use. 

🔧 Maintenance

We also noticed some differences between Clearly Filtered and Berkey when it came to maintenance. 

Here’s how we scored both systems for their servicing requirements and costs. 

ProductMaintenance ScoreServicing RequirementsCosts
Clearly Filtered8.75Outstanding$0.55/ gal
Big Berkey8.50Weak$0.13/ gal

Clearly Filtered got the better overall score for maintenance because it was easier to service. 

Servicing Requirements 

The Clearly Filtered pitcher and Big Berkey system have one key maintenance requirement in common: they both need their filters replacing once they become saturated with contaminants. 

Once again, we had a much easier ride with Clearly Filtered here. Although we had to replace the filters more frequently (around once every 4 months on average), the filter priming process was quicker and simpler. Washing out the pitcher and reservoir – which we did once or twice a week – was also simple thanks to the pitcher’s small, uncomplicated design. 

The Big Berkey was more difficult to maintain because we had to go through the same time-consuming filter priming process whenever we replaced the filters. 

Thankfully, Berkey’s projected filter lifespan is much longer than Clearly Filtered’s (a pair of Black Berkey elements has a capacity of 6,000 gallons), so we haven’t had to replace our filters yet. 

We have, however, followed Berkey’s advice to clean the elements with a Scotch Brite pad every 3-6 months, which improves flow rate by removing some of the accumulated debris. While this was an extra task to remember, we were keen to do anything to avoid having to prime a new pair of filters.  

We also washed out our Berkey chambers to keep them clean. 

Neither Berkey nor Clearly Filtered use a filter change timer, so we made our own phone calendar reminders and kept an eye on filtration rate. 

Maintenance Costs

The Big Berkey is cheaper to maintain than the Clearly Filtered pitcher, so it got the better score in this subcategory. 

Clearly Filtered has a cost per gallon of $0.55. The main reason why it’s costlier than the Big Berkey in the long run is that its filter lifespan is significantly shorter. We’d have to replace the filters roughly 3-4 times a year, which racks up the ongoing cost.

Berkey costs $0.13 per gallon to use and maintain. We calculated this cost by combining the ongoing cost of two Black Berkey elements ($0.034/gallon) and two fluoride filters ($0.09/gallon).

So, Berkey might be expensive upfront, but you should be able to spend less on maintenance costs – assuming that Berkey’s projected filter lifespan is accurate

🏢 Company

We think a manufacturer’s warranty, shipping, and returns policy offerings say a lot about the company itself. Here, we’ve compared Clearly Filtered and Berkey as companies. 

Good to Know: Berkey units are sold by a number of third-party distributors rather than by the manufacturer. We’ve reviewed in this section, as one of the most popular Berkey distributors at the moment. 
ProductCompany ScoreWarranty LengthShippingReturns
Clearly Filtered9.002 yearsFree shipping, all orders to all states30 days
Big Berkey9.10LifetimeFree shipping on orders over $99 to the lower 48 states30 days

Both companies impressed us here, but Berkey won by a margin. 

Warranty Length 

Clearly Filtered’s 2-year warranty is the best warranty offering we’ve come across from a water filter pitcher manufacturer. goes one step further, offering a lifetime warranty against manufacturing defects. Incidentally, this is the best warranty we’ve seen from a countertop water filter manufacturer. 


Clearly Filtered offers a better shipping policy: all US customers receive free economy shipping, regardless of their spend. 

Customers must spend at least $99 to be eligible for’s free shipping, and they must live in one of the lower 48 states. 


Clearly Filtered and Berkey both have a 30-day returns policy, entitling customers to a refund if they return their system within 30 days of the date of purchase.  

⛔️ System Setbacks & Flaws

Both Berkey and Clearly Filtered could benefit from a couple of design improvements. From our own experience using these systems, we identified the following unique setbacks and flaws: 

Clearly Filtered Setbacks

  • Only certified to reduce some contaminants – We definitely value the fact that Clearly Filtered has a certified performance, while Berkey doesn’t. But we’d like to see a certification for additional contaminants reduced, like lead and chromium-6
  • Majority plastic design – Unlike Berkey, Clearly Filtered houses filtered water in a plastic container. You may prefer to use non-plastic water storage solutions. 
  • Needs more refills – The Clearly Filtered pitcher’s 10-cup water-holding capacity means it needs to be refilled far more frequently than the 2.25-gallon Big Berkey. 

Berkey Setbacks

  • Not certified – The biggest setback of the Big Berkey unit is that it isn’t certified for its contaminant reduction abilities and also lacks a materials safety certification.
  • Fluoride filter issues  – In our first test, the unit’s fluoride filters introduced high concentrations of activated alumina into our water. 
  • Potential rusting issue – We’ve read reviews from some customers complaining that their supposedly stainless steel water chambers started to rust. However, we can’t validate the legitimacy of these reviews. 
  • Water overflowing/leaking – We were unable to view inside the Berkey’s bottom water chamber without taking the unit apart. This led us to accidentally overfill the top chamber, causing water to overflow out between the two chambers. 

🆚 Clearly Filtered or Berkey: Which Do We Recommend?

We think the Big Berkey and Clearly Filtered systems are both good choices for countertop water filtration, but, depending on your situation, one filter may be better for you than the other. 

We’ve listed the scenarios where Clearly Filtered or Berkey might be your best choice. 

You’ll Prefer Clearly Filtered If:

You want to spend less than $100 on a water filter upfront.
You want a smaller countertop water filter that can be carried from room to room.
Certifications for design and performance are a non-negotiable for you.

Choose Berkey If:

You have a large family or want to be able to filter and store large batches of water.
You prefer a system made from a non-plastic material, with a reduced risk of plastic leaching.
You want a unit with a long filter life that’s affordable to maintain in the long run.
  • Brian Campbell
    President & CEO, CWS, CWR

    Brian Campbell, a WQA Certified Water Specialist (CWS) and Certified Water Treatment Representative (CWR) with 5+ years of experience, helps homeowners navigate the world of water treatment. After honing his skills at Hach Company, he founded his business to empower homeowners with the knowledge and tools to achieve safe, healthy water. Brian's tested countless devices, from simple pitchers to complex systems, helping his readers find the perfect fit for their unique needs.

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