APEC RO-90
#3 in With tankFull review
For buyers who want a certified, low-maintenance tank RO system with long-lasting filters.
Amazon $209.99$209.99
The APEC RO-90 is the better under-sink reverse osmosis system overall, rated 3.8 to 3.0. The APEC RO-90 leads on certification and filter cost. The Express Water ROALK10MBN wins on output. The Express Water ROALK10MBN costs $10 less ($199.99 vs $209.99).
Express Water ROALK10MBN
#9 in With tankFull review
For a buyer who wants mineralized water at a low price. The RO5DX is the safer pick if certification matters.
Amazon $199.99$199.99
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 APEC RO-90 for certification (certified to NSF/ANSI 58 vs not certified to NSF/ANSI 58; certified to NSF/ANSI 372) and filter cost ($73 a year in replacement filters vs $143 a year in replacement filters).
- Choose the Express Water ROALK10MBN for output (100 gallons a day vs 90 gallons a day).
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 | APEC RO-90 | Express Water ROALK10MBN |
|---|---|---|
| Overall rating | 3.8/5 | 3.0/5 |
| Certification 25% | 100 certified to NSF/ANSI 58 | 30 not certified to NSF/ANSI 58; certified to NSF/ANSI 372 |
| Filter cost 20% | 77 $73 a year in replacement filters | 35 $143 a year in replacement filters |
| Water wasted 15% | 50 drain ratio not published (neutral score used) | 50 drain ratio not published (neutral score used) |
| Output 10% | 80 90 gallons a day | 100 100 gallons a day |
| Price 15% | 72 $209.99 | 76 $199.99 |
| Warranty 15% | 0 1-year warranty | 0 1-year warranty |
Specifications
| APEC RO-90 | Express Water ROALK10MBN | |
|---|---|---|
| Filtration | ||
| Output | 90 gallons a day | 100 gallons a day |
| Stages | 5 | 10 |
| Remineralization | No | Yes |
| NSF/ANSI 58 | Yes | No |
| Other certifications | NSF/ANSI 372 | NSF/ANSI 372 |
| Replacement filters | $73 a year | $143 a year |
| Build | ||
| Tank | 4 gal | - |
| Booster pump | No | No |
| Smart faucet | No | No |
| Warranty | 1 year | 1 year |