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 3.1. The Delta Clarifi Tankless RO leads on certification. The Frizzlife PD600-TAM3 wins on price and filter cost. The Frizzlife PD600-TAM3 costs $399.51 less ($399.49 vs $799).
Frizzlife PD600-TAM3
#11 in TanklessFull review
For a buyer who wants mineralized tankless RO with low running costs and accepts maker test claims instead of NSF 58 certification.
Amazon $399.49$399.49
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).
- Choose the Frizzlife PD600-TAM3 for price ($399.49 vs $799) and filter cost ($117 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 | Frizzlife PD600-TAM3 |
|---|---|---|
| Overall rating | 3.7/5 | 3.1/5 |
| 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 | 47 $117 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 | 63 $399.49 |
| Warranty 15% | 100 5-year warranty | 0 warranty not published, scored as none |
Specifications
| Delta Clarifi Tankless RO | Frizzlife PD600-TAM3 | |
|---|---|---|
| Filtration | ||
| Output | 600 gallons a day | 600 gallons a day |
| Pure to drain | 2:1 | 2:1 |
| Stages | 6 | 8 |
| Remineralization | No | Yes |
| NSF/ANSI 58 | Yes | No |
| Other certifications | NSF/ANSI 42, 53, 244, 372, 401 | NSF/ANSI 372 |
| Replacement filters | $201 a year | $117 a year |
| Build | ||
| Tank | Tankless | Tankless |
| Booster pump | - | Yes |
| Smart faucet | - | No |
| Warranty | 5 years | - |
| Released | 2024 | - |