
Express Water RO5DX
Score: 88/100
Aquasana SmartFlow
Score: 88/100Rankings

The Express Water RO5DX is a compact 5-stage under-sink reverse osmosis system featuring NSF/ANSI 58 certification and alkaline remineralization for improved taste. It offers a 50 GPD production rate and includes a leak detection shutoff for added safety. While it lacks the high capacity of larger systems, its pre-assembled design and remineralization feature make it a strong contender for standard households.

The Aquasana SmartFlow® Reverse Osmosis Water Filter System is a high-efficiency under-sink filtration unit that combines Claryum® technology with reverse osmosis to remove up to 99.99% of 90 contaminants. It features patented SmartFlow® technology to reduce water waste and extend filter life, along with a remineralization stage to improve pH balance and alkalinity. The system is best suited for health-conscious households seeking comprehensive contaminant removal and mineral-enriched water.
| Attribute | ![]() | ![]() |
|---|---|---|
5 stagesbest | 4 stages | |
50 gallons per daybest | 25.7 gallons per day | |
96 percent | 96.4 percentbest | |
4 gallonsbest | 2.5 gallons | |
1,000 countbest | 90 count | |
12 monthsbest | — | |
| ↓ lower better | 5 inches | 4.5 inchesbest |
| ↓ lower better | 15 inches | 12.93 inchesbest |
Click an attribute name to sort · Green = best, red = worst (relative to this comparison)
| Attribute | ![]() | ![]() |
|---|---|---|
Compliance & Safety(1) | ||
Certifications | NSF/ANSI 58 | WQA Certified |
Storage(1) | ||
Storage Tank Capacity (gallons) | 4 gallons | 2.5 gallons |
Maintenance(1) | ||
Filter Lifespan (months) | 12 months | months |
Design(2) | ||
System Width (inches) | 5.0 inches | 4.5 inches |
System Height (inches) | 15.0 inches | 12.93 inches |
Performance(6) | ||
Filtration Stages (stages) | 5 stages | 4 stages |
Daily Production Rate (gallons per day) | 50 gallons per day | 25.7 gallons per day |
TDS Reduction Rate (percent) | 96 percent | 96.4 percent |
Wastewater Ratio | Standard | Low Waste |
Contaminants Removed (count) | 1000 count | 90 count |
Feed Water Pressure (PSI) | 40 PSI | 40-80 PSI |
Features(2) | ||
Faucet Type | Chrome | Dedicated Faucet |
Automatic Shutoff | true | |

Products in the top-left offer the best value (high score, low price).

Professional reviewers highlight the RO5DX's NSF/ANSI 58 certification as a key strength, validating its TDS reduction capabilities and material safety.
Users generally praise the system for its reliable performance, compact size, and the peace of mind provided by NSF certification.



Expert reviewers highlight the Aquasana SmartFlow® system for offering one of the highest certified contaminant removal rates among reverse osmosis systems. The patented SmartFlow® technology is specifically praised for reducing water waste and extending filter life beyond average RO systems.
The search results provided do not contain specific consumer reviews or everyday user feedback regarding common praise or recurring complaints.