A cheaper way to get fluoride filters in the box than the TK-FS, with silver in the carbon filters.
Amazon $199.99The Waterdrop TK-AB-FS is the better gravity water filter overall, rated 3.3 to 3.0. The Waterdrop TK-AB-FS leads on certification. The Waterdrop TK-AE costs $10 less ($189.99 vs $199.99).
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 people who want faster flow than a two-filter 2.25 gal system and can do without a certification claim.
Amazon $189.99Which should you buy?
- Choose the Waterdrop TK-AB-FS for certification (states certification to NSF/ANSI 42, NSF/ANSI 372 vs no certification or test claim published).
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-AB-FS | Waterdrop TK-AE |
|---|---|---|
| Overall rating | 3.3/5 | 3.0/5 |
| Value 25% | 64 $88.88 per gallon of capacity ($199.99, 2.2 gal) | 67 $84.44 per gallon of capacity ($189.99, 2.2 gal) |
| Running cost 15% | 50 replacement cost or element life not published (neutral score used) | 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 | 11 1-year warranty |
Specifications
| Waterdrop TK-AB-FS | Waterdrop TK-AE | |
|---|---|---|
| Capacity and flow | ||
| Tank capacity | 2.2 gal | 2.2 gal |
| Price per gallon of capacity | $88.88 | $84.44 |
| Elements included | 4 | 3 |
| Maximum elements | 4 | 3 |
| Filtration | ||
| Element type | Coconut shell carbon block with silver ions (black) | Coconut shell carbon filter (black) |
| Certified | NSF/ANSI 42, NSF/ANSI 372 | None stated |
| Certification detail | Listing title: NSF/ANSI 42&372 Standard. The listing text does not say which component is certified. | Listing makes no certification claim for this three-filter model. |
| Fluoride | Included | - |
| Fluoride element life | 1,000 gal | - |
| Running cost | ||
| Rated life per element | 3,000 gal each | 3,000 gal each |
| Build | ||
| Material | 304 stainless steel | 304 stainless steel |
| Warranty | 1 year | 1 year |
