Ultra Filtration vs UV: What’s Best for Bacteria and Beyond?
In New Zealand, UV disinfection systems are widely used for treating rural water sources. But when it comes to truly protecting your household from the broad range of microscopic contaminants in modern water—Ultra Filtration (UF) may be the smarter long-term solution.
Let’s break it down.
The Common Ground: Pre-Filtration
Whether you use UV or UF, you’ll typically start with pre-filtration down to 1 micron. This removes sediment, silt, and cloudiness so either system can work properly.
But once the water is clear, you have a choice:
| Option A | Option B |
|---|---|
| Install UV to sterilize bacteria with light | Install Ultra Filtration to physically remove bacteria—and a lot more |
Both cost about the same. Both need maintenance (bulb change or filter change). So what’s the difference?
What Do They Actually Remove?
| Contaminant | Ultra Filtration (0.01–0.2 µm) | UV Disinfection |
|---|---|---|
| Bacteria (e.g., E. coli) | Yes (physically removed) | Yes (sterilised if exposed) |
| Parasites (Giardia, Crypto) | Yes | No |
| Microplastics | Yes | No |
| Fine sediment & silt | Yes | No |
| Viruses (e.g., Norovirus) | Yes at 0.001 µm or less | Yes (if exposed) |
| Algae | Yes | Yes (if exposed) |
Conclusion: Ultra Filtration physically removes a wider range of contaminants—including visible and invisible particles. UV only sterilises bacteria and viruses—it does not remove them or anything else.
Reliability & Maintenance
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|---|
A Real-World Example
Let’s say both systems use a 1-micron sediment filter upfront. Now compare:
| Feature | Ultra Filtration System | UV System |
|---|---|---|
| Power outage? | Still works | Stops working |
| Missed filter change? | Slows down | Still flows—might not treat |
| Bacteria in cloudy rainwater? | Removed physically | May pass through |
| Microplastics from roof/tanks? | Filtered out | Untouched |
What's More Common Internationally?
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UV is common in New Zealand, Australia, and Canada due to older infrastructure and habits.
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Ultra Filtration is widely used in Europe and Asia, where rising concerns about microplastics, parasites, and modern water safety have led to more advanced approaches.
Our Recommendation
If you're starting with clean, clear water—and just want to kill bacteria, UV will do the job.
But if you want to physically remove bacteria, parasites, microplastics, silt, and even some viruses—without relying on power or light—then Ultra Filtration is the superior, more reliable, and future-proof solution.
Ultra Filtration Systems we sell
Akla Flow, Alka City Total, Alka Ultra , ultra Microbial, Lifespring enriched Rural, PureRevive (Technically not.. but even better)