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
The Delta Clarifi Tankless RO is the better under-sink reverse osmosis system overall, rated 3.7 to 3.4. The Delta Clarifi Tankless RO leads on certification and warranty. The Waterdrop G2P600 wins on price and filter cost. The Waterdrop G2P600 costs $500 less ($299 vs $799).
Waterdrop G2P600
#7 in TanklessFull review
For a buyer who wants tankless RO at a low price and low running cost and can do without third-party performance certification.
Amazon $299$299
Prices were last checked November 2, 2026 and are subject to change; the price and availability shown by the retailer at the time of purchase apply.
Which should you buy?
- Choose the Delta Clarifi Tankless RO for certification (certified to NSF/ANSI 58 vs not certified to NSF/ANSI 58; certified to NSF/ANSI 372) and warranty (5-year warranty vs 1-year warranty).
- Choose the Waterdrop G2P600 for price ($299 vs $799) and filter cost ($80 a year in replacement filters vs $201 a year in replacement filters).
Scores side by side
Each factor is scored 0-100 against the same fixed reference points for every tankless under-sink reverse osmosis system; a clear win is highlighted. How we rank explains each one.
| Factor weight | Delta Clarifi Tankless RO | Waterdrop G2P600 |
|---|---|---|
| Overall rating | 3.7/5 | 3.4/5 |
| Certification 25% | 100 certified to NSF/ANSI 58 | 30 not certified to NSF/ANSI 58; certified to NSF/ANSI 372 |
| Filter cost 20% | 13 $201 a year in replacement filters | 71 $80 a year in replacement filters |
| Water wasted 15% | 95 2:1 pure to drain | 95 2:1 pure to drain |
| Output 10% | 43 600 gallons a day | 43 600 gallons a day |
| Price 15% | 9 $799 | 86 $299 |
| Warranty 15% | 100 5-year warranty | 0 1-year warranty |
Specifications
| Delta Clarifi Tankless RO | Waterdrop G2P600 | |
|---|---|---|
| Filtration | ||
| Output | 600 gallons a day | 600 gallons a day |
| Pure to drain | 2:1 | 2:1 |
| Stages | 6 | 7 |
| Remineralization | No | No |
| NSF/ANSI 58 | Yes | No |
| Other certifications | NSF/ANSI 42, 53, 244, 372, 401 | NSF/ANSI 372 |
| Replacement filters | $201 a year | $80 a year |
| Build | ||
| Tank | Tankless | Tankless |
| Booster pump | - | Yes |
| Smart faucet | - | No |
| Warranty | 5 years | 1 year |
| Released | 2024 | - |