APEC RO-Hi
#4 in With tankFull review
For cooks and families who fill pots and pitchers often and want a faster pour from a certified tank system.
Amazon $299.94$299.94
3.6/5
For a budget buyer who wants a certified system with cheap filters. Anyone paying for water or on a septic system should pick a lower waste design.
- 50 gallons a dayOutput
- $81 a yearFilters
- YesNSF/ANSI 58
Check price at Amazon$179.99
Price checked November 2, 2026. As an Amazon Associate we earn from qualifying purchases.
Pros
- Certified to NSF/ANSI 58 by NSF
- Filters cost about $81 a year
- Among the cheapest certified systems
- Includes a leak stop valve
Cons
- A lab test measured over five gallons down the drain per gallon made
- Slow 50 gallon a day output
- One year warranty
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 | - | 51.8 gpd | - | At 48 psi and 58.6 F. |
| Water Filter Guru | - | - | 0.2 :1 | 64 oz purified to 336 oz drained (1:5.25); a 12 oz test gave 1:5.9. |
Specifications
| Model number | RO5DX |
|---|---|
| Filtration | |
| Output | 50 gallons a day |
| Stages | 5 |
| Remineralization | No |
| NSF/ANSI 58 | Yes |
| Other certifications | NSF/ANSI 372 |
| Replacement filters | $81 a year |
| Build | |
| Tank | 3.2 gal |
| Booster pump | No |
| Smart faucet | No |
| Warranty | 1 year |
Alternatives in this type
iSpring RCC7AK
#5 in With tankFull review
For buyers who want certified RO water with minerals added back for taste, at a low price. Choose a tankless system instead if cabinet space or wasted water matters more.
Amazon $199.99$199.99
APEC ROES-50
#7 in With tankFull review
For a small household that wants a certified tank RO system at a low price. Larger families should look at the ROES-100.
Amazon $179.99$179.99
Compare
Compare the Express Water RO5DX with any other under-sink reverse osmosis system →
More from Express Water: every Express Water product ranked.