UV Purification Systems
Updated February 20, 2026
Use ultraviolet light to kill bacteria, viruses, and other microorganisms. Chemical-free water disinfection for well water and municipal water.
Overview
UV purification systems use ultraviolet light to kill bacteria, viruses, and other microorganisms in water. The UV lamp inside a stainless steel chamber exposes water to UV-C radiation (254 nanometers) as it flows through, destroying the DNA of pathogens and rendering them unable to reproduce. Chemical-free disinfection -- no chlorine, no taste change, no byproducts. Essential for well water and any private water source where bacterial contamination is a risk. Often paired with sediment and carbon filtration for comprehensive treatment.
Pros & Cons
- Chemical-free
- Kills bacteria and viruses
- Low operating cost
- No taste change
- Doesn't remove chemicals
- Requires pre-filtration
- Needs electricity
Key Features
- Kills 99.99%% of bacteria, viruses, and protozoa without chemicals
- No taste or odor change to the water -- purely physical disinfection
- Whole-house installation treats all water entering the home
- Flow rates from 6-25+ GPM for residential applications
- UV lamp requires annual replacement; quartz sleeve requires periodic cleaning
Sizing & Selection
Size by flow rate: the UV system must handle your home peak flow rate. A typical 3-bedroom home needs 8-12 GPM. Larger homes or homes with irrigation may need 15-25 GPM. The UV dose (measured in mJ/cm2) must be at least 40 for NSF Class B (supplemental) or 16 for basic disinfection. Higher dose provides a safety margin.
Installation
Install on the main water line after any sediment and carbon pre-filters but before the distribution to the house. The UV chamber mounts vertically (most common) on the pipe with union connections for easy removal. Requires a nearby electrical outlet for the UV controller/ballast. Pre-filtration is critical -- sediment and turbidity block UV light and create shadows where organisms hide.
Maintenance
- Replace the UV lamp annually (-80) regardless of whether it still lights. UV output decreases over time even though the lamp appears to work.
- Clean the quartz sleeve every 6-12 months. Mineral buildup on the sleeve blocks UV transmission.
- Replace the quartz sleeve every 2-3 years or if cracked/clouded.
- Monitor the UV intensity indicator (included on quality systems). If it drops below the minimum dose, replace the lamp immediately.
- Change pre-filters on schedule -- turbid water passing through UV is not fully treated.
Buying Tips
- Viqua (Trojan Technologies) and HALO are the top residential UV brands. Both NSF certified.
- Always install sediment and carbon pre-filtration before UV. UV cannot treat turbid or chemically contaminated water effectively.
- A UV system does NOT remove chemicals, heavy metals, or dissolved solids. It only kills organisms. Pair with appropriate filtration for comprehensive treatment.
- Well water users: UV is essential. Have your water tested annually for coliform bacteria even with UV installed.
- Budget -800 for the system, -80/year for lamp replacement. A small price for guaranteed safe water.