A well-priced 2.25 gal system with certified carbon filters. The easy pick if you want Berkey-size capacity for less.
Amazon $159.99The Waterdrop TK-A is the better gravity water filter overall, rated 3.5 to 2.9. The Waterdrop TK-A leads on certification and value. The Waterdrop TK-A costs $69.01 less ($159.99 vs $229).
Prices were last checked November 9, 2026. Product prices and availability are accurate as of that date and are subject to change; the price and availability shown on Amazon or the retailer's site at the time of purchase apply. As an Amazon Associate we earn from qualifying purchases.
For homes with fluoridated water they would rather not drink. Plan on replacing the fluoride filters much sooner than the carbon ones.
Amazon $229Which should you buy?
- Choose the Waterdrop TK-A for certification (states certification to NSF/ANSI 42, NSF/ANSI 372 vs no certification or test claim published) and value ($71.11 per gallon of capacity ($159.99, 2.2 gal) vs $101.78 per gallon of capacity ($229, 2.2 gal)).
Scores side by side
Each factor is scored 0-100 against the same fixed reference points for every up to 2.25 gal gravity water filter; a clear win is highlighted. How we rank explains each one.
| Factor weight | Waterdrop TK-A | Purewell 2.25G 8-Stage Fluoride |
|---|---|---|
| Overall rating | 3.5/5 | 2.9/5 |
| Value 25% | 78 $71.11 per gallon of capacity ($159.99, 2.2 gal) | 56 $101.78 per gallon of capacity ($229, 2.2 gal) |
| Running cost 15% | 75 $0.012 per gallon filtered ($34.99 per element, 3,000 gal each) | 50 replacement cost or element life not published (neutral score used) |
| Capacity 15% | 17 2.2 gal tank | 17 2.2 gal tank |
| Certification 20% | 40 states certification to NSF/ANSI 42, NSF/ANSI 372 | 0 no certification or test claim published |
| Element life 15% | 100 3,000 gal rated per element | 100 3,000 gal rated per element |
| Warranty 10% | 11 1-year warranty | 0 warranty not published, scored as none |
Specifications
| Waterdrop TK-A | Purewell 2.25G 8-Stage Fluoride | |
|---|---|---|
| Capacity and flow | ||
| Tank capacity | 2.2 gal | 2.2 gal |
| Price per gallon of capacity | $71.11 | $101.78 |
| Elements included | 2 | 4 |
| Maximum elements | 2 | 4 |
| Filtration | ||
| Element type | Coconut shell carbon filter (black) | Black carbon filters plus white fluoride filters |
| Certified | NSF/ANSI 42, NSF/ANSI 372 | None stated |
| Certification detail | Listing: system passed NSF/ANSI 372 (lead-free materials) and the black carbon filter is certified to NSF/ANSI 42 for chlorine, taste and odor. | Listing makes no certification claim for this model. |
| Fluoride | Add-on filter | Included |
| Fluoride element life | - | 1,000 gal |
| Running cost | ||
| Rated life per element | 3,000 gal each | 3,000 gal each |
| Replacement element | 35 $ | - |
| Cost per gallon filtered | $0.012 | - |
| Build | ||
| Material | 304 stainless steel | 304 stainless steel |
| Height | - | 20 in |
| Diameter | - | 8.8 in |
| Warranty | 1 year | - |
