The entry Culligan MaxClear with a certified filter for people who want a name-brand 2.25 gal system at a low price.
Amazon $155
The Waterdrop with fluoride filters in the box. Costs $80 more than the TK-A, which can take fluoride filters as an add-on.
- 2.2 galCapacity
- NSF/ANSI 42, NSF/ANSI 372Certification
- 3,000 gal eachElement life
- IncludedFluoride
Price checked November 9, 2026. As an Amazon Associate we earn from qualifying purchases.
- Ships with two carbon and two fluoride filters
- Sight-glass spigot and stand included
- Fluoride filters last only 1,000 gallons
- Listing does not claim certification for fluoride reduction
The Waterdrop King Tank family
Every Waterdrop King Tank model we rank, smallest first. Ratings compare each against its own capacity.
| Model | Capacity | Rating | Price |
|---|---|---|---|
| Waterdrop TK15-A | 1.5 gal | 3.4/5 | $119.99 |
| Waterdrop TK-A | 2.2 gal | 3.5/5 | $159.99 |
| Waterdrop TK-AE | 2.2 gal | 3.0/5 | $189.99 |
| Waterdrop TK-AB-FS | 2.2 gal | 3.3/5 | $199.99 |
| Waterdrop TK-FS (this one) | 2.2 gal | 3.3/5 | $239.99 |
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.
Specifications
| Model number | WD-TK-FS |
|---|---|
| Capacity and flow | |
| Tank capacity | 2.2 gal |
| Price per gallon of capacity | $106.66 |
| Elements included | 4 |
| Maximum elements | 4 |
| Filtration | |
| Element type | Coconut shell carbon filter (black) |
| Certified | NSF/ANSI 42, NSF/ANSI 372 |
| Certification detail | Listing: system certified to NSF/ANSI 372 and the black carbon filter to NSF/ANSI 42. The listing does not say the fluoride filters are certified. |
| Fluoride | Included |
| Fluoride element life | 1,000 gal |
| Running cost | |
| Rated life per element | 3,000 gal each |
| Replacement element | 35 $ |
| Cost per gallon filtered | $0.012 |
| Build | |
| Material | 304 stainless steel |
| Warranty | 1 year |
Alternatives in this capacity
A small, low-priced certified gravity filter for one to three people, a trip or an RV.
Amazon $119.99A cheaper way to get fluoride filters in the box than the TK-FS, with silver in the carbon filters.
Amazon $199.99Compare
Compare the Waterdrop TK-FS with any other gravity water filter →
More from Waterdrop: every Waterdrop product ranked.