Best Countertop Water Filter in 2025? We Tested 26 Systems!

Countertop Water Filter Reviews

Prefer reading a guide? Below are our countertop water filter reviews in text form! However, we’ve only included the filters we consider worth mentioning. At the end you will find a list of all the countertop water filters we tested and that were part of this comparison but didn’t make the cut.

1. Best Overall + Highest Filtration Score: AquaTru Classic

Final Rating: 4.83/5.00

In our opinion, the AquaTru Classic (which is a reverse osmosis system) is the best countertop water filter available right now, primarily because it offers highly effective water filtration backed by excellent results in our lab testing as well as all the important NSF certifications for contaminant reduction and paired with great usability and affordable costs!

Sara’s Video Review

Filtration: 5.00/5.00

With 5.00 out of 5.00, the AquaTru Classic achieved the highest filtration score out of all 26 countertop water filters. That’s because it did great in our lab testing, it has all the important NSF certifications, and the filtered water tasted and smelled perfectly clean.

1. Lab Results: 4.97/5.00

In our lab testing, the AquaTru Classic could remove all undesirable impurities and contaminants in our tap water to below the minimum detection level with the only 2 exceptions being strontium and fluoride.

• But strontium was reduced by 96% so almost perfect.
• For fluoride we calculated a minimum reduction rate of 41%. But the actual reduction rate was probably in the nineties, because the AquaTru Classic is NSF-certified for fluoride reduction with an average reduction rate of 93.5% according to the official performance data sheet, so highly effective.

The only issue is that the AquaTru Classic might have leached a tiny amount of aluminum into the filtered water – the lab detected 0.05 ppm. This isn’t ideal obviously, but it was well below even the strictest health guideline on aluminum we could find which is set to 0.6 ppm.

Lab Results Chart

2. NSF Certifications and Other Test Data

The AquaTru Classic is certified for contaminant reduction by the IAPMO against NSF standards 42, 53, 58, and 401. All the important contaminants are covered – we counted 85 substances in total – including dozens of VOCs (up to 99% reduction), arsenic 5 (98%), chromium 6 (97.2%), fluoride (93.5%), lead (99.1%), nitrate (87.2%), chloramine (96%), so-called emerging contaminants (around 90-95%), and PFOA & PFOS (97.5%).

This makes the AquaTru Classic really stand out from the competition. In fact, we don’t know of a single countertop water filter except the AquaTru Carafe reviewed below that can even remotely compete with that.

Usability: 5.00/5.00

The AquaTru Classic is incredibly easy to set up, use, and maintain (a filter life indicator will tell you when to replace filters). Filtration speed (10-15 minutes per 1-gallon cycle) is also good and you can dispense water quickly (1.5 cups in 4 seconds). We also like that both the feed water tank and clean water tank are removable which allows for easy refilling and you can even store your filtered water in the fridge.

Our only issue: Our unit didn’t work at first presumably because water got into the front handle. But we could resolve this easily by letting the handle dry.

Costs: 4.16/5.00

As of Jan 20, 2025, the AquaTru Classic is available for $449. But using one of our special deals you can purchase the system for as little as $349 which we find surprisingly cheap. Plus, we estimate $100-120 in annual filter replacement costs which seems totally fine.

Additional Ranking Factors

• In our wastewater test, the AquaTru Classic wasted 0.6 gallons per 1 gallon of purified water, which is really good although some of the other countertop RO systems we tested wasted even less.
• Checking third-party customer complaints we stumbled upon issues with leaking and malfunctioning systems.

Read Our Full AquaTru Classic Review

2. Best Countertop RO for Lower Budgets: AquaTru Carafe

Final Rating: 4.66/5.00

Based on our analysis, the AquaTru Carafe is the best countertop RO water filter for people on a lower budget – if you use our product link you qualify for a $100 discount and so the AquaTru Carafe is available for just $259 – and for those who want a glass container for storing their purified reverse osmosis water.

Sara’s Video Review

Filtration: 4.74/5.00

The AquaTru Carafe achieved a filtration score of 4.74/5.00 which means that, together with a few other filters, it comes in at second place right after the AquaTru Classic in our countertop water filter comparison.

The reason why the AquaTru Carafe did so well was because it proved to be highly effective in our lab testing and, just like the AquaTru Classic, it has all the important NSF certifications and the filtered water it provided tasted and smelled perfectly clean.

1. Lab Results: 4.49/5.00

In our lab testing, the AquaTru Carafe could remove most undesirable impurities and contaminants in our tap water to below the minimum detection level. Exceptions were boron, strontium, and fluoride.

• Boron was removed by 60% so not bad but also not perfect and several of the other countertop filters we tested (primarily the other countertop ROs) achieved higher reduction rates of up to 100%.
• But at 98% strontium reduction, the AquaTru Carafe was pretty much perfect.
• Fluoride was reduced by 67% so, again, some of the other countertop filters (primarily the other RO systems) did slightly better. That said, the AquaTru Carafe is NSF standard 58-certified for fluoride reduction with an average reduction rate of 96.4% according to the official performance data sheet – in other words: Highly effective.

Finally, it might have been that the AquaTru Carafe leached a tiny amount of aluminum – the lab measured 0.01 ppm in the unfiltered and 0.04 ppm in the filtered water. So this is similar to the AquaTru Classic and not ideal. But 0.04 ppm aluminum is well below even the strictest health guideline on aluminum we could find which is set to 0.6 ppm.

Lab Results Chart

2. NSF Certifications and Other Test Data

Similar to the AquaTru Classic, the AquaTru Carafe is certified for contaminant reduction by the IAPMO against NSF standards 42, 53, 58, and 401. All the important contaminants are covered – we counted 82 in total. Reduction rates as listed in the performance data sheet include dozens of VOCs (up to 99%), arsenic 5 (98.8%), chromium 6 (97.5%), fluoride (96.4%), lead (99.2%), nitrate (98.3%), chloramine (96.6%), emerging contaminants (around 90-99%), PFOA & PFOS (99%), and microplastics (98.96%).

This makes the AquaTru Carafe clearly stand out from the competition and only the AquaTru Classic reviewed above can compete with that.

Usability: 5.00/5.00

The AquaTru Carafe is very easy and straightforward to set up, use, and maintain (a filter life indicator will let you know when to replace one of the filters using the included tool). Inserting the carafe triggers the filtration cycle. One full cycle (around 0.66 gallons) takes 10 to 15 minutes to complete so totally acceptable. Also, the 0.5-gallon carafe has a good size for everyday use and because it’s removable you can store it in your fridge. We also like that the feed water tank is removable for easy refilling.

Costs: 4.08/5.00

As of Jan 20, 2025, the AquaTru Carafe is available for $359. But using our special deal you can purchase it for $100 off, so just $259 making the AquaTru Carafe a real budget pick. For annual filter replacements, we estimate $150 which we also find totally acceptable.

Additional Ranking Factors

• The AquaTru Carafe collects all purified water in its carafe which is made from borosilicate glass, so no issues with potential contamination that might originate from a plastic container.
• In our wastewater test, the AquaTru Carafe wasted 0.44 gallons for each purified gallon that you can use, which is really good although there were still a few other countertop ROs we tested that wasted even less.
• Checking third-party customer complaints we read reports about units that didn’t last very long.

Read Our Full AquaTru Carafe Review

3. Countertop RO Alternative: Bluevua RO100ROPOT

Final Rating: 4.42/5.00

We recommend the Bluevua RO100ROPOT as our #1 countertop RO alternative to the AquaTru Classic/Carafe. The Bluevua RO100ROPOT performed great in our testing overall and especially in our lab testing. The biggest downside to the system is the lack of NSF certifications for contaminant reduction (2 certifications for TDS and chromium 3 reduction are pending).

Sara’s Video Review

Filtration: 4.50/5.00

The Bluevua RO100ROPOT achieved a filtration score of 4.50/5.00 and as such was on par with the AquaTru Carafe, coming in at second place right after the AquaTru Classic in our countertop water filter comparison.

In summary, the Bluevua RO100ROPOT did really well in our lab testing and the taste and odor of the filtered water provided was excellent, but the system lacks behind in NSF certifications for contaminant reduction.

1. Lab Results: 5.00/5.00

In our lab testing, the Bluevua RO100ROPOT could remove almost all of our undesirable tap water impurities and contaminants to below the minimum detection level. The only exceptions were boron, strontium, and fluoride.

• Boron was removed by 90% and only 6 other countertop filters we tested could achieve a higher reduction rate of 100%.
• 98% strontium reduction was pretty much perfect.
• For fluoride, the Bluevua achieved a minimum reduction rate of 76% which means that only a few countertop filters in our test including the AquaTru Classic can compete with it here.

Lab Results Chart

2. NSF Certifications and Other Test Data

Unlike the AquaTru Classic and Carafe, the Bluevua RO100ROPOT isn’t certified against any NSF standards for contaminant reduction yet, although 2 certifications against NSF 58 for TDS and chromium 3 reduction are pending apparently. In other words, the Bluevua RO100ROPOT really falls behind here which is the main reason why it didn’t become our top recommendation.

A small plus: Bluevua does provide additional test data, but apparently the testing was performed against standards outside the NSF spectrum, and it looks like contaminant reduction was only tested at the startup of operating life (whereas genuine NSF certifications require testing throughout the entire filter life).

Usability: 5.00/5.00

The Bluevua RO100ROPOT is very easy and straightforward to set up, use, and maintain. You have the option to filter and dispense 3 different water volumes: 0.13, 0.26, and 0.45 gallons. Based on our speed test, dispensing 0.45 gallons should take around 6 and a half minutes which is fast for an RO but still requires some patience if you filter on demand. Also, you have the option to pour straight into a glass or into the included 0.5-gallon carafe which has a good size for everyday use, and because it’s removable you can store it in your fridge. We also like that the feed water tank is removable for easy refilling. There’s also a filter life indicator and a live TDS display to monitor your system and determine the ideal time to replace filters.

Costs: 3.62/5.00

As of Jan 20, 2025, the Bluevua RO100ROPOT is available for $434 which is more on the high end of all 10 countertop reverse osmosis systems we tested as part of this guide. For annual filter replacements, we estimate $120-150 based on the rated filter life. However, as mentioned above we lack most NSF certifications, so we think it’s quite possible that the rated filter life is too optimistic and getting the best filtration results would require more frequent replacements adding to the cost.

Additional Ranking Factors

• The Bluevua RO100ROPOT collects all purified water in its carafe which is made from borosilicate glass, so no issues with potential contamination that might originate from a plastic container.
• In our wastewater test, the system wasted 1.03 gallons for each purified gallon that you can use, which was the second highest wastewater ratio.
• The only complaint that came up frequently in 3rd-party user ratings was the glass carafe being a bit too fragile.

Read Our Full Bluevua RO100ROPOT Review

4. Best/Most Effective Regular Countertop Water Filter #1: Aquasana Clean Water Machine

(Use Code AQBOS50 for Up to 50% Off!)

Final Rating: 4.32/5.00

Together with the ZeroWater 32-Cup Ready-Read Dispenser, we recommend the Aquasana Clean Water Machine (a.k.a. Aquasana CWM) as the best – as in most effective – regular countertop water filter, a countertop water filter that doesn’t rely on reverse osmosis. Most importantly, we saw good but not perfect filtration results in our lab testing and we have several NSF certifications.

Filtration: 4.22/5.00

The Aquasana Clean Water Machine achieved a filtration score of 4.22/5.00, the second best among all non-RO systems in our countertop water filter comparison.

In summary, the Aquasana CWM achieved solid results in our lab testing, taste and odor of the filtered water provided was flawless, and the system is backed by several NSF certifications for contaminant reduction although they are mostly limited to organic compounds which we consider easier to remove.

1. Lab Results: 4.22/5.00

In our lab testing, the Aquasana CWM could remove most undesirable tap water impurities and contaminants to below the minimum detection level. Exceptions were:

• Boron which was removed by 80% so that several RO and non-RO countertop filters we tested could achieve higher reduction rates of up to 100%.
• Strontium which was reduced by 93%, so almost perfect.
• Fluoride which was not reduced at all, but this is typical for countertop filters that don’t apply reverse osmosis.

In addition, there was a tiny amount of aluminum detected in the filtered water which hadn’t been detected in our raw tap water sample. However, this might just be coincidence. And even if the Aquasana Clean Water Machine did leach the aluminum, the detected level of just 0.01 ppm was 60 times below the strictest aluminum health guideline we could find, which is set to 0.6 ppm as mentioned before – so nothing to worry about.

One lab result that concerns us a bit more is the 0.96 ppb of methylene chloride detected in the filtered water. Although still below the strictest health guideline we could find (4 ppb), we’re much closer to reaching that guideline compared to the potential aluminum leaching.

Lab Results Chart

2. NSF Certifications and Other Test Data

The Aquasana CWM is certified for contaminant reduction by the WQA against NSF standards 42, 53, and 401. We counted 77 substances covered in total, but with a few exceptions such as chlorine (97.3% reduction), chloramine (97.6%), lead (99.6-99.7%), mercury (96.2-96.6%), and asbestos (99%), they are mostly limited to organic compounds – think emerging contaminants (around 99 to 99%), PFOA & PFOS (95.2%), and VOCs (up to 99%). We consider these organics easier to remove and so, in our opinion, NSF certification is great to have but less important here. At the same time, we miss certifications for the reduction of arsenic 5, chromium 6, nitrate, nitrite, and a few other important chemicals.

By the way, you can check the official performance data sheet here.

Usability: 4.50/5.00

The Aquasana CWM is easy and straightforward to set up, use, and maintain. In our speed test, the Aquasana CWM could filter and dispense 12 ounces within 15 seconds which we feel is fast enough even to filter water on demand. Also, there’s a filter life indicator light that tells you when to replace filters.

Our only issue: The feed water tank misses a handle and it doesn’t sit very tight and thus seems prone to getting knocked out because it’s relatively high and narrow.

Costs: 4.43/5.00

As of Jan 20, 2025, the regular price tag for the Aquasana Clean Water Machine is $399.99 and the discounted price is $199.99. But this discount isn’t always available unless you use our exclusive code – don’t forget! Still, at $199.99 the price for the Aquasana CWM is definitely on the high end for this kind of system. On the upside, we estimate $60 in annual filter replacements based on the rated filter life which is highly affordable, and you can save an extra 15% with a filter subscription!

Additional Ranking Factors

• We like the looks of the system.
• There’s a 90-day satisfaction guarantee.
• Checking third-party customer complaints, we read about malfunctioning systems that didn’t last very long, leaking, dripping that continues for a while after dispensing, loud pump noises, taste issues, and difficulties removing the filter or filter chamber cap.

Read Our Full Aquasana CWM Review

(Use Code AQBOS50 for Up to 50% Off!)

5. Best/Most Effective Regular Countertop Water Filter #2: ZeroWater 32-Cup Ready-Read Dispenser

Final Rating: 3.89/5.00

Together with the Aquasana CWM, we recommend the ZeroWater 32-Cup Ready-Read Dispenser as the best/most effective regular countertop water filter, so one that doesn’t rely on RO. Why? The ZeroWater 32-Cup holds a few important NSF certifications for contaminant reduction and is backed by additional (NSF) testing. Plus, in our 2 rounds of lab testing the filter element we saw great results. However, the filter might have issues dealing with chloroform/disinfection byproducts (and possibly other organics) which are highly abundant in tap water and associated with adverse health effects. We also don’t like the “0 TDS approach”. And, the system is extremely expensive to maintain.

Filtration: 4.31/5.00

The ZeroWater 32-Cup Ready-Read Dispenser achieved a filtration score of 4.31/5.00 (the best among all non-RO systems) in our countertop water filter comparison.

In summary, we’ve lab-tested the filter element used by the ZeroWater 32-Cup twice – once in the 32-cup dispenser itself and once using a fresh cartridge in the ZeroWater 10-Cup Ready-Pour Pitcher – and both times it achieved exceptional reduction rates for most undesirable impurities. However, we found problems with potential copper leaching and lackluster reduction of chloroform. Taste and odor of the filtered water was flawless, and although missing most organics the system is backed by a few important NSF certifications for contaminant reduction + additional NSF and other testing.

1. Lab Results: 4.81/5.00

In our second round of lab testing of the ZeroWater filter element (installed in the ZeroWater 32-Cup dispenser) which we conducted as part of this countertop water filter comparison, it could remove all undesirable tap water impurities to below the minimum detection level except:

• Chloroform, which wasn’t reduced at all. 2 other testers got similar results independently from us: The EWG (82% average reduction of disinfection byproducts) and Modern Castle (~40% reduction of chloroform). The problem with lackluster filtration of chloroform/disinfection byproducts (or maybe even organic compounds in general) is that they are highly abundant in tap water often exceeding their strictest health guidelines and associated with adverse health effects such as bladder cancer.
• Fluoride, which was reduced by at least 75% which is outstanding and at least as good as any of the other countertop filters (including RO systems) we’ve tested.

In our first round of lab testing the ZeroWater filter element (installed in the ZeroWater 10-Cup Ready-Pour Pitcher) which we had conducted as part of our water filter pitcher comparison, it could remove all undesirable tap water impurities to below the minimum detection level except copper, boron, and fluoride.

• For copper we saw a 1,100% concentration increase from 0.01 to 0.12 ppm. We think the ZeroWater filter element might have leached some of its KDF media which is a mixture of copper and zinc. This leaching isn’t ideal, but at 40% of the strictest health guideline for copper in drinking water we could find, we are also not overly concerned.
• For boron we saw a 75% reduction so not perfect but still solid.
• And for fluoride we saw a minimum reduction rate of 78% so yet again really outstanding (although it might be possible that the fluoride reduction results from our pitcher comparison are flawed).

And finally, for our first round of testing there was a tiny amount of aluminum detected in the filtered water which hadn’t been detected in the raw water sample. However, this might just be coincidence and even if not, the detected level of 0.01 ppm was 60 times below the strictest aluminum health guideline (0.6 ppm) we could find, so nothing to worry about.

And by the way, in both rounds of testing we did see a TDS reduction in our water close to 100% as claimed by ZeroWater. But we don’t like this TDS focus (learn more here).

Lab Results Chart for Testing of the ZeroWater 32-Cup Ready-Read Dispenser

2. NSF Certifications and Other Test Data

The ZeroWater 32-Cup is certified for contaminant reduction by the IAPMO against NSF standards 42 and 53, and by the NSF against standards 42 and 53. We counted 7 analytes covered in total including lead (95.9-99.7%), PFOA/PFOS (94.9%), and chromium 6 (99.6%). Especially chromium 6 is very rare for any non-RO water filter so this is great (check the official performance data sheet here)!

ZeroWater also provides additional in-house contaminant reduction test data with some of the testing conducted against NSF against standards 42 and 53 and for the full filter life. The results look good although they’re mostly limited to metals and salts and we miss reduction rates for most organic compounds.

Usability: 4.50/5.00

The ZeroWater 32-Cup Ready-Read Dispenser is easy to set up, use, and maintain. But, the plastic handle used to dispense water seems a bit small. In our speed test, the system could filter and dispense 12 ounces within 3:02 minutes which should be fast enough for regular use. There’s no filter life indicator but a TDS meter which you’re supposed to use to determine the ideal time to replace filters (once the meter reads “006” or higher). In our opinion, there’re pros and cons to this approach (learn more here).

Costs: 2.00/5.00

As of Jan 20, 2025, the regular price tag for the ZeroWater 32-Cup is $44.99 which is pretty average for this type of countertop filter. But provided you replace filters based on their rated life of only 15 to 17 gallons, you’ll spend anywhere between $380 and $430 a year – much more compared to the direct competition! – if you consume 500 gallons of filtered water.

Additional Ranking Factors

• The system has a slim and space-saving design.
• The plastic reservoir feels like it could be prone to cracking.
• Short 90-day warranty.
• Checking third-party customer complaints, we read about taste/odor issues, slow filtration and clogged filters, leaking filters, and faulty TDS meters.

Read Our Full ZeroWater 32-Cup Ready-Read Dispenser Review

6. Best Regular Countertop Filter for Lower Budgets: Waterdrop ED04

(Use Code ED04BOS for 3% Off on Top of Most Waterdrop Sales!)

Final Rating: 4.07/5.00

The Waterdrop ED04 turns out to be the best countertop filter budget pick among all non-RO systems. Naturally, the Waterdrop ED04 is highly affordable both upfront and in the long-term. This is combined with decent results in our lab testing, clean taste and odor of the filtered water, a bunch of NSF certifications for contaminant reduction, great usability, and nice looks!

Filtration: 3.45/5.00

The Waterdrop ED-04 achieved a filtration score of 3.45/5.00. In our lab testing, the system could remove most water contaminants to 100%, but 5 were only partially removed or not at all. Taste and odor of the filtered water provided was still flawless. We also have a high count of NSF-certified contaminants but they are mostly limited to organic compounds which we consider easier to remove.

1. Lab Results: 3.45/5.00

In our lab testing, the Waterdrop ED04 could remove 8 undesirable tap water impurities to below the minimum detection level, while traces of 5 impurities remained in the water:

• Boron was removed by 40% which isn’t that good compared to most of the competition.
• Strontium was reduced by 77% so at a lower rate compared to the countertop filters reviewed above and also compared to several other systems that are part of this guide (primarily ROs), but the difference isn’t that large.
• Nitrate was removed by 42% – again not great compared to most of the competition.
• Fluoride wasn’t reduced at all, but this is typical for countertop filters that don’t apply reverse osmosis.
• Uranium wasn’t reduced at all. But to be fair uranium was at the lowest possible concentration, and maybe we would have seen at least some reduction if pre-filtration levels had been a little higher.

Finally, there was a tiny amount of aluminum detected in the filtered water which hadn’t been detected in the raw water sample. As usual, this might just be a coincidence and even if not, the detected level of 0.03 ppm was 20 times below the strictest aluminum health guideline we could find, so we’re not worried about this at all.

Lab Results Chart

2. NSF Certifications and Other Test Data

The Waterdrop ED04 is certified for contaminant reduction by the IAPMO against NSF standards 42, 53, and 401. We counted 33 analytes covered and the performance data sheet (included in manual) lists these reduction rates among others: Chlorine (97%), lead (99.6%), MTBE (98.64%), 2,4-D (99.8%), and 15 emerging compounds (between 94 and 99%). However, certification is mostly limited to organic compounds. We consider these easier to remove and so, in our opinion, NSF certification is great to have but less important here. At the same time, we miss certification for the reduction of pentavalent arsenic, hexavalent chromium, nitrate/nitrite, etc.

Usability: 5.00/5.00

The Waterdrop ED-04 is easy to set up, use, and maintain. A USB-rechargeable battery is used to run the system including pump so there’s no power connection required for higher portability. In our speed test, the system could filter and dispense 12 ounces within 25 seconds (relatively slow for a non-RO system) which means filtering on-demand requires a bit of patience. An indicator light will let you know when to replace filters.

Costs: 5.00/5.00

As of Jan 20, 2025, the regular price for the Waterdrop ED04 is $59.99 which seems like a steal. Also, the system is often on discount and you can use our exclusive code which will grant you another 3% off on top of almost any current Waterdrop sale! We estimate $60 in annual filter replacements based on the rated filter life which again is highly affordable, and you can save an extra 5% with a filter subscription!

Additional Ranking Factors

• Nice looks!
• Checking third-party customer complaints, we read about malfunctioning filter life indicators, units that stopped working entirely, leaking, taste issues, and unresponsive dispensing buttons.

Read Our Full Waterdrop ED04 Review

(Use Code ED04BOS for 3% Off on Top of Most Waterdrop Sales!)

7. Best Gravity-Type Countertop Filter: Big Berkey

(Use Code BOS5 for 5% Off When You Buy From bigberkeywaterfilters.com!)

Final Rating: 4.08/5.00

In our opinion, the Big Berkey is the best of all 7 gravity-type countertop water filters we’ve tested, especially because it scored highest in our lab testing among said filters. However, there’re restocking issues with the Black Berkey filter elements which is definitely something that needs to be taken into account before purchasing.

Filtration: 3.98/5.00

The Big Berkey achieved a filtration score of 3.98/5.00. In our lab testing, the system could remove almost all undesirable impurities to 100%. Also, taste and odor of the filtered water provided was flawless. Unfortunately, we don’t have any NSF certifications for contaminant reduction. Instead, the Big Berkey was tested by third-party labs against a whole bunch of contaminants and with most of the testing against NSF standards. But, at least some of the testing was not performed for the entire filter life.

1. Lab Results: 4.48/5.00

Please note: We calculated a lab score of 4.48/5.00 based on our lab results and our recommendation to skip the optional fluoride filters.

In our lab testing, the Big Berkey could remove all undesirable tap water impurities to below the minimum detection level, except:

• Strontium which was reduced by 98% so almost perfect.
• Nitrate which was removed by 8%. This isn’t great obviously and several other countertop water filters that were part of our lab testing performed better.
• Fluoride which was reduced by 67% so not that bad actually. However, this reduction rate could only be achieved because we lab-tested the Black Berkey filters in combination with Berkey’s optional PF-2 fluoride filters. These PF-2 filters are based on activated alumina (or aluminum oxide) and it looks like they leached some of their filter media into our water – the lab detected 1.01 ppm of some form of aluminum. This aluminum leaching was also found by at least 1 other tester and, based on our research, it might be a health issue (learn more here). And so we would advise to skip the optional fluoride filters to be on the safe side. But, this probably also means that fluoride reduction goes down considerably.

Lab Results Chart

2. NSF Certifications and Other Test Data

The Big Berkey has no official NSF certifications for contaminant reduction. Instead, the system was tested by third-party labs against NSF standards 42 and 53. We counted 152 substances here which is a lot. Berkey also provides additional test data where we’re not sure if testing was performed against NSF standards and if so which standards were used. What we know is that at least some of the testing was not performed for the entire filter life. All lab results can be found here.

Usability: 4.00/5.00

The Big Berkey is easy to assemble, use, and maintain. Initial filter priming was a bit slow but got much faster by the second round of filtration. In our speed test, the system could filter and dispense 4 cups within 40:44 minutes – we added 2 gallons into the top reservoir and used 2 Black Berkey filter elements including 2 PF-2 addon filters in parallel. Thus, you can’t filter on-demand but the 2.25-gallon filtered water storage should be large enough to not run out of filtered water if you plan ahead. Also, you can use up to 4 filter elements in parallel which would double your filtration speed, and you might get an extra boost by skipping the fluoride filters.

Costs: 4.44/5.00

As of Jan 20, 2025, the price for the Big Berkey is $367 without fluoride filters which is above average for such a countertop/gravity water filter – at least we have a 5% discount code that you can use if you buy from bigberkeywaterfilters.com. For annual filter replacements and before the restocking issue, we used to estimate $186 when using 2x Black Berkey filters in parallel and no fluoride filters. This estimate is based on an adjusted filter life of 500 gallons (learn more here). Around $186 a year still seems reasonable also given the fact that the filters are made in USA.

Additional Ranking Factors

• 304 stainless steel tanks.
• 1-year to lifetime warranty on the system excluding filter elements.
• 3rd-party customers complained about leaking dispensers.

Read Our Full Big Berkey Review

(Use Code BOS5 for 5% Off When You Buy From bigberkeywaterfilters.com!)

8. Budget Gravity-Type Filter Ideal for Nitrate Removal: Purewell

Final Rating: 3.83/5.00

We recommend the Purewell only if you really want a gravity-type countertop water filter. In this category, the Purewell didn’t perform as well overall as the Big Berkey, but the system is much more affordable making it our top budget pick. Also, if nitrate removal is your #1 priority, the Purewell did much better than the Big Berkey in our lab testing. Finally, there are restocking issues with the Big Berkey filters, so from that perspective the Purewell might be the better choice right now.

Filtration: 3.41/5.00

The Purewell home gravity filter scored a decent 3.41/5.00 on filtration, which is okay for its price point. In our lab test, most contaminants were removed to 100%, but a few weren’t reduced much, and one even increased considerably. Still, the taste and odor of the filtered water were flawless. That said, it’s also worth mentioning that Purewell has no NSF certifications for actual contaminant reduction. Plus, the company did only limited contaminant reduction testing and hasn’t verified its claim of a 3,000-gallon filter lifespan.

1. Lab Results: 4.41/5.00

Please note: We calculated a lab score of 4.41/5.00 based on our lab results and our recommendation to skip the optional fluoride filters.

Generally, the Purewell removed most unwanted contaminants to below the minimum detection level, except:

• Barium was removed by 75%, comparable to the other gravity-type filters we tested.
• Lithium had 0% removed, which was the same among all the home gravity filters we tested except for the Big Berkey which achieved 100%. That said, lithium was at the lowest possible concentration and maybe we would have seen a higher reduction rate if pre-filtration levels had been higher.
• Strontium was 61% removed, our second-best gravity filter score.
• Fluoride wasn’t reduced at all (it even increased by 47% presumably due to natural fluctuations), although we used the optional fluoride filters.
• Some form of aluminum increased from undetected to 0.19 ppm, presumably due to leaching from the optional fluoride filters (they’re made with activated alumina). And because said filters apparently didn’t reduce fluoride levels in our water anyway, we recommend skipping them which should solve the aluminum leaching issue.
• Manganese increased from none detected to 0.01 ppm, but that’s also the minimum that the lab can detect, so it could be a coincidence, and it’s still lower than CDC health guidelines which seem to be the most reasonable.

Lab Results Chart

2. NSF Certifications and Other Test Data

While Purewell advertises NSF certification, this is for material safety, not contaminant reduction. For the Purewell gravity filter, the company only tested contaminant reduction on a single small sample for chlorine, mercury, and lead, so we cannot confirm the 3,000-gallon lifespan they claim. Finally, they tested 99.99% E. coli reduction in non-potable water. But if you’re dealing with non-potable water, we’d definitely recommend boiling followed by disinfection as the go-to treatment methods.

All contaminant reduction test data can be found here.

Usability: 4.00/5.00

The Purewell gravity water filter was very easy to set up, use (also thanks to tank stand and water level window on lower tank), and maintain. The initial filter priming was slow, but in our speed test, the system filtered and supplied 4 cups of drinking water in a little more than 1 hour (again, we added 2 gallons into the top reservoir and used 2 Black Filters and 2 addon fluoride filters in parallel), making the Purewell the third-fastest gravity system. So while you can’t filter on demand, the 2.25-gallon storage capacity should supply enough drinking water if you plan ahead.

Costs: 4.94/5.00

As of January 2025, the Purewell system costs $159 with two Black Filters and one tank stand, making it our favorite gravity filter budget pick. However, while Purewell claims their Black Filters can last 3,000 gallons, there’s no test data to confirm it. So we recommend replacing them sooner like every 500 gallons or every 6 months. In this case, your yearly costs will be about $140 which still seems pretty low.

Additional Ranking Factors

• 304 stainless steel tanks and all metal handles and spigots.
• Vague return policy of only 30 days “with reasonable reason”.
• Company website doesn’t convey a lot of trust.
• 3rd-party customers complained about taste issues, clogged filters, and leaking.

Read Our Full Purewell Review