Delta Clarifi Tankless RO
#3 in TanklessFull review
For a household that wants a broadly certified tankless system with low running costs and a long warranty. Budget buyers can get similar output for less.
Amazon $799$799
3.5/5
For a large household that wants the fastest flow and lowest waste, and will pay a premium for it.
- 1,200 gallons a dayOutput
- 3:1Pure to drain
- $173 a yearFilters
- YesNSF/ANSI 58
Check price at Amazon$1,099
Price checked November 2, 2026. As an Amazon Associate we earn from qualifying purchases.
Pros
- Very fast output, enough for filling pots and large bottles without waiting
- Wastes little water for an RO system
- Certified to NSF/ANSI 58
- Adds minerals back and shows water quality on the faucet
Cons
- Expensive to buy
- Filters cost more than most rivals
- Needs a power outlet under the sink
How it scores
The rating comes from 6 measured or published factors, each scored 0-100 against fixed reference points for its type. How we rank explains each one.
Independent measurements
Dissolved solids reduction, output and drain ratio measured by independent testers.
| Tested by | TDS reduction | Output | Pure to drain | Conditions |
|---|---|---|---|---|
| Water Filter Guru | 81.3 % | - | - | Tap Score lab: 235 ppm kitchen tap feed to 44 ppm from the X12 faucet (81.28%), Westminster, Colorado city water; output includes the added minerals. Date is the review update date. |
Specifications
| Model number | WD-X12 |
|---|---|
| Filtration | |
| Output | 1,200 gallons a day |
| Pure to drain | 3:1 |
| Stages | 11 |
| Remineralization | Yes |
| NSF/ANSI 58 | Yes |
| Other certifications | NSF/ANSI 42 |
| Replacement filters | $173 a year |
| Build | |
| Tank | Tankless |
| Booster pump | Yes |
| Smart faucet | Yes |
| Warranty | 2 years |
Alternatives in this type
Waterdrop G3P600
#4 in TanklessFull review
For a household that wants a certified tankless RO system with a smart faucet at a mid-range price. Its NSF 58 listing is the main reason to pick it over cheaper tankless units.
Amazon $439$439
Waterdrop G3P800
#6 in TanklessFull review
For a busy kitchen that wants fast RO water and low waste from a certified system, and can pay for it.
Amazon $849$849
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