Short answer
Both technologies use a "membrane", but they do different jobs. The short answer: if you want to remove dissolved salts, choose RO; if you want microbiological safety and clarity, choose UF.
Comparison
| Ultrafiltration (UF) | Reverse osmosis (RO) | |
|---|---|---|
| Pore size | ~0.01 µm | ~0.0001 µm |
| Removes | Suspended solids, turbidity, bacteria, viruses, colloids | What UF removes + dissolved salts, heavy metals, nitrate, silica |
| Minerals | Retained | 95–99% removed |
| Operating pressure | 0.5–3 bar | 8–16 bar (well), 50–70 bar (sea) |
| Water loss | 5–10% (backwash) | 25–50% (concentrate) |
| Energy | Low | Medium to high |
| Typical use | Drinking water, surface water pretreatment, SDI reduction before RO | Boiler feed water, process water, dialysis, high-TDS wells |
Which one when?
- Mains water, drinking water quality as the target, minerals to be kept → UF + UV is enough.
- Well water, TDS > 500 ppm, boiler or process use → RO is a must, with multimedia/UF pretreatment ahead of it.
- Surface water, high turbidity → UF pretreatment + RO (for SDI < 3).
- Coffee, tea, beverages → RO + remineralisation, or NF.
Using them together
In industrial plants, the most robust arrangement is UF → RO: UF protects the membrane and RO removes the salts; RO membrane life is extended and CIP frequency drops. You can use our RO calculator for the capacity calculation and request a quote together with your water analysis.
