Purewell 9-Stage Fluoride BO-FL
#12 in Up to 2.25 galFull review
A fluoride-focused Purewell with one filter type to stock. Running costs are higher than for the carbon-only models.
Amazon $209$209
2.2 galNone stated1,000 gal each
2.6/5
The best known countertop gravity filter, sized for a small family. Priced well above lookalikes with the same capacity.
- 2.2 galCapacity
- Tested onlyCertification
- 3,000 gal eachElement life
- Add-on filterFluoride
Check price at Amazon$367
Price checked November 9, 2026. As an Amazon Associate we earn from qualifying purchases.
Pros
- 2.25 gal serves roughly one to four people
- Expands to four elements for a 7 gal/hr maximum flow
Cons
- Not NSF certified; the maker only states third-party testing
- A genuine replacement pair costs far more than for Purewell or Waterdrop elements
The Berkey family
Every Berkey model we rank, smallest first. Ratings compare each against its own capacity.
| Model | Capacity | Rating | Price |
|---|---|---|---|
| Travel Berkey | 1.5 gal | 2.4/5 | $327 |
| Big Berkey (this one) | 2.2 gal | 2.6/5 | $367 |
| Berkey Light | 2.8 gal | 2.8/5 | $335 |
| Royal Berkey | 3.2 gal | 2.9/5 | $408 |
| Imperial Berkey | 4.5 gal | 3.2/5 | $451 |
| Crown Berkey | 6 gal | 3.5/5 | $478 |
How it scores
The rating comes from 6 measured or published factors, each scored 0-100 against fixed reference points for its capacity. How we rank explains each one.
Independent tests
Lab and bench tests by independent reviewers.
| Tested by | Conditions |
|---|---|
| Water Filter Guru | Reviewers calculated 0.75 gal/hr with two Black Berkey and two PF-2 fluoride elements installed (volume and time not given). Tap Score lab tests of city tap water found aluminum 0 ppm before and 1.44 ppm after at 50 gal, then 0.052 ppm before and 0.069 ppm after in a second test with over 100 gal run through the fluoride filters; no TDS reported. Date is the review update date. |
Specifications
| Model number | BK4X2-BB |
|---|---|
| Capacity and flow | |
| Tank capacity | 2.2 gal |
| Price per gallon of capacity | $163.11 |
| Elements included | 2 |
| Maximum elements | 4 |
| Flow, fully loaded | 7 gal/hr |
| Filtration | |
| Element type | Black Berkey carbon-media element (BB9-2) |
| Certified | Tested only |
| Certification detail | Berkey states Black Berkey Elements were tested by accredited third-party labs against ANSI/NSF protocols for 200+ contaminants. The elements are not NSF/ANSI certified. |
| Fluoride | Add-on filter |
| Running cost | |
| Rated life per element | 3,000 gal each |
| Replacement element | 140.9 $ |
| Cost per gallon filtered | $0.047 |
| Build | |
| Material | 304 stainless steel |
| Height | 19.2 in |
| Diameter | 8.5 in |
| Warranty | 1 year |
Alternatives in this capacity
Boroux Compact 1.8 Gal
#13 in Up to 2.25 galFull review
A small stainless gravity filter for one or two people with long-life filters. It costs more per gallon of tank than larger rivals.
Amazon $349$349
1.8 galNSF/ANSI/CAN 3726,000 gal each
Glacier Fresh PC04
#15 in Up to 2.25 galFull review
A newer 2.25 gal system with a different filter technology. Short filter life makes it expensive to run.
Amazon $169.99$169.99
2.2 galTested only200 gal each
Compare
Compare the Big Berkey with any other gravity water filter →
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