Ultraviolet disinfection
How a UV Purifier works
Shines UV light through the water to inactivate bacteria, viruses, and other microbes — no chemicals.
Typical cost: $200–$900 installed
How it works
A UV purifier passes water through a chamber lined with a high-output ultraviolet lamp. The UV-C light scrambles the DNA of bacteria, viruses, and cysts so they can't reproduce or make you sick.
It adds no chemicals and changes nothing about taste — it only disinfects. Because UV can't penetrate cloudy water, a sediment pre-filter is required so the light reaches every microbe.
The lamp is housed in a clear quartz sleeve and runs continuously; it's replaced about once a year to keep output strong (NSF/ANSI 55).
The components inside
What each part does, in the order water moves through the system.
- 1Sediment pre-filterClears particles so UV light can reach the water.
- 2UV reactor chamberStainless vessel where water is exposed to the lamp.
- 3UV-C lampEmits the germicidal light that inactivates microbes.
- 4Quartz sleeveProtects the lamp from the water while passing UV through.
- 5Controller / ballastPowers the lamp and signals when it needs replacing.
What it addresses
- Inactivates bacteria, viruses, and protozoan cysts
- No chemicals added; taste and minerals unchanged
- Does NOT remove sediment, metals, or chemical contaminants
Pros & cons
Pros
- Highly effective microbial disinfection without chemicals
- Doesn't alter taste, odor, or mineral content
- Low maintenance — mainly an annual lamp swap
Cons
- Only works on clear water — needs a sediment pre-filter
- No residual protection downstream of the unit
- Needs continuous power and an annual lamp replacement
Best for
Wells or any supply with a microbial (bacteria) concern that needs chemical-free disinfection.
Sizing basics
- Sized by flow rate (GPM) so every drop gets a full UV dose.
- Higher flow needs a larger reactor or a higher-output lamp.
- Always paired with a sediment pre-filter for clear water.
Next steps
Know the tech — now see real systems, get a price, or find someone local to install it.
Sources
Explore other system types
Advertising disclosure
The Very Good Water Company is an authorized WaterTech dealer and earns revenue from installations and lead referrals.