Express Water RO5DX
#6 in With tankFull review
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.
Amazon $179.99$179.99
The Express Water RO5DX is the better under-sink reverse osmosis system overall, rated 3.6 to 2.6. The Express Water RO5DX leads on certification, price and filter cost. The Home Master TMHP HydroPerfection wins on warranty. The Express Water RO5DX costs $319.96 less ($179.99 vs $499.95).
Home Master TMHP HydroPerfection
#14 in With tankFull review
For well water homes that want UV and an iron prefilter with low water waste. On treated city water the cheaper TMAFC-ERP does the same job.
Amazon $502.06 Home Master $499.95$499.95
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 Express Water RO5DX for certification (certified to NSF/ANSI 58 vs no third-party certification), price ($179.99 vs $499.95) and filter cost ($81 a year in replacement filters vs $163 a year in replacement filters).
- Choose the Home Master TMHP HydroPerfection for warranty (5-year warranty vs 1-year warranty).
Scores side by side
Each factor is scored 0-100 against the same fixed reference points for every with tank under-sink reverse osmosis system; a clear win is highlighted. How we rank explains each one.
| Factor weight | Express Water RO5DX | Home Master TMHP HydroPerfection |
|---|---|---|
| Overall rating | 3.6/5 | 2.6/5 |
| Certification 25% | 100 certified to NSF/ANSI 58 | 0 no third-party certification |
| Filter cost 20% | 70 $81 a year in replacement filters | 27 $163 a year in replacement filters |
| Water wasted 15% | 50 drain ratio not published (neutral score used) | 82 1:1 pure to drain |
| Output 10% | 0 50 gallons a day | 0 50 gallons a day |
| Price 15% | 85 $179.99 | 0 $499.95 |
| Warranty 15% | 0 1-year warranty | 100 5-year warranty |
Independent measurements
Express Water RO5DX
| 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. |
Home Master TMHP HydroPerfection
No independent test published yet.
Specifications
| Express Water RO5DX | Home Master TMHP HydroPerfection | |
|---|---|---|
| Filtration | ||
| Output | 50 gallons a day | 50 gallons a day |
| Pure to drain | - | 1:1 |
| Stages | 5 | 9 |
| Remineralization | No | Yes |
| NSF/ANSI 58 | Yes | No |
| Other certifications | NSF/ANSI 372 | - |
| Replacement filters | $81 a year | $163 a year |
| Build | ||
| Tank | 3.2 gal | 3.2 gal |
| Booster pump | No | No |
| Smart faucet | No | No |
| Warranty | 1 year | 5 years |