The Express Water RO5DX is the entry-level pick for buyers who want under-sink RO filtration at the lowest possible upfront cost. Here's an honest look at what you get and what corners are cut at this price point.
The RO5DX delivers legitimate 5-stage RO filtration at a price that undercuts iSpring and APEC significantly. The trade-off is fewer certifications, less established track record, and customer support that isn't as reliable as iSpring's lifetime support from Georgia or APEC's Houston team. For budget-constrained buyers who want real RO filtration: it works. For buyers who can stretch to $180–$220: the iSpring RCC7AK is meaningfully better.
| Filtration stages | 5-stage (sediment, GAC, carbon block, RO membrane, post-carbon) |
| Flow rate | 75 GPD |
| Storage tank | 3.2 gallons (included) |
| Waste ratio | ~1:3 |
| RO membrane accuracy | 0.0001 micron |
| Certifications | Tested to NSF standards — fewer independent certifications than iSpring/APEC |
| Installation | Under-sink DIY, 1–2 hours |
| Annual filter cost | ~$50–$70 |
| Remineralization | Not included |
If your budget can stretch to $180–$220, the iSpring RCC7AK gives you NSF 58 full-system certification, alkaline remineralization, and lifetime technical support from a US-based team. That's a meaningfully better long-term buy for a modest extra investment.
Express Water RO5DX on Amazon →