Current RKIN product documentation and replacement-filter schedule. We did not physically test the U1.
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Best for renters and premium countertop buyers who value hot/cold dispensing as much as purification.
U1 is not the cheapest way to get RO water. Its advantage is integration: no plumbing, instant-hot water, chilled water, remineralization, hydrogen, app features and published third-party contaminant testing. If you only need room-temperature RO, cheaper systems make more sense.
RKIN U1-W at a glance
| System type | Countertop, zero-installation RO |
| RO membrane | 200 GPD |
| Purified storage | About ½ gallon |
| Production time | About ½ gallon in under 7 minutes |
| Pure-to-waste | About 1:1 |
| Temperature options | Ambient, chilled, instant hot |
| Dimensions | 9.5 W × 17 H × 19 D in |
| Weight | 26 lb |
| Current list price | About $875 |
RKIN publishes unusually specific contaminant testing for a countertop appliance
RKIN states that U1 is third-party tested for reduction of TDS, fluoride, lead, PFOA/PFOS, hexavalent chromium and trivalent chromium. That is more useful than a generic “RO removes contaminants” claim, though buyers should still inspect the exact test documentation when a specific health-related contaminant is the reason for purchase.
The system also uses a carbon/sediment prefilter, RO membrane, alkaline post-filter, UV and a hydrogen module. Some of those stages affect taste or convenience rather than contaminant-removal performance, so they should not be treated as interchangeable evidence.
The real cost is proprietary consumables plus a complex appliance
RKIN specifies replacement of the sediment/carbon filter every 6–12 months, RO membrane every 12–24 months, alkaline post-filter every 6–12 months, and hydrogen module every 6–12 months. The current 2-year filter bundle is over $300, so long-term consumable cost is material.
U1's complexity is also its biggest downside. Heating, cooling, app connectivity and hydrogen add convenience but create more components that can fail versus a simple under-sink RO system.
RKIN U1 questions
Does RKIN U1 require installation?
No plumbing installation is required. You fill the removable feed tank and place it on the countertop system.
What contaminants is RKIN U1 tested for?
RKIN states third-party testing for reduction of TDS, fluoride, lead, PFOA/PFOS, hexavalent chromium and trivalent chromium.
How much purified water does U1 make?
RKIN states the U1 holds about half a gallon of filtered water and can produce that amount in under seven minutes.
Who is the U1 best for?
It is best suited to buyers who want no-plumbing RO plus hot and chilled dispensing in one appliance and are comfortable with a higher purchase price and proprietary filters.