Express Water RO5DX
A NSF-certified reverse osmosis filter that is certified to reduce 1 contaminant.
You want the most thorough filtration — the only common type that removes fluoride, arsenic, and dissolved solids. Accept some water waste.
Certified to reduce 1 contaminants.
Reverse osmosis wastes some water (a few gallons per gallon produced) and strips beneficial minerals along with contaminants — the trade-off for the most thorough filtration. Expect a storage tank and slower flow.
What is reverse osmosis system? A multi-stage under-sink system that forces water through a semi-permeable membrane, removing the widest range of contaminants — including dissolved ones carbon can’t touch. Compare all filter types →
What it costs to own
| Upfront price | — |
| Replacement filter | — |
| Estimated yearly cost (filters, ~1×/yr) | — |
| True cost per gallon | — |
Cost per gallon and yearly cost are our estimates from the rated capacity and the Amazon price. We show them only when we read the price from Amazon in the last 24 hours. The filter only works if you replace it on schedule.
What it's certified to remove
Certification is per-contaminant: the Express Water RO5DX is credited only for the contaminants listed here, verified by NSF. It does not imply removal of anything not listed.
✓ Verify this certification on the official NSF listing →
Full specifications
| Certified by | NSF |
| NSF/ANSI standards | 58 — reverse osmosis — removes dissolved solids, fluoride, and arsenic |
| Filter type | Reverse osmosis system |
| Installation | Under-sink system with a dedicated faucet and storage tank. |
Frequently asked
Is the Express Water RO5DX NSF certified?
Yes — the Express Water RO5DX is listed in the NSF certified-product database under NSF/ANSI standard 58. That means an independent body verified its claims (not just "tested to" a standard).
What does the Express Water RO5DX remove?
It is certified to reduce 1 contaminants: Total dissolved solids.
How often do you replace the reverse osmosis filter?
A reverse osmosis filter like this is typically replaced about 1 time a year. Replace on schedule — a spent cartridge stops reducing contaminants.
Compare similar reverse osmosis filters
Source: NSF public certification listing. Specs and certified claims are from the official listing; cost figures are our estimates. Some links are affiliate links — see our disclosure.