A UV water purifier works by targeting waterborne microorganisms that make water unsafe for consumption. The process is natural and is effective against 99.99% of all living pathogens. Stubborn microbes like Giardia which other methods cannot treat, do not stand a chance against UV light.

The system can work with running water or from a storage tank. Among other advantages, UV purifiers ensure you get safe drinking water all year round. Apart from home use, campers and bikers can carry a portable UV system to guarantee clean water for drinking.

Most UV systems come standardized. To effectively use the system, you need to do a water analysis. The report will inform you which pathogens are in the water and what UV intensity you require to kill them.

Maintaining a UV purifier is critical. After 9,000 hours of use, the system becomes ineffective. Replacing the lamp is the only sure way to keep the system working.

Does UV Disinfection Work Against All Microorganisms?

To a large extent, this is true. UV light can effectively kill most bacteria, protozoa, and viruses. Microorganisms like giardia offer resistance to lower intensity UV light. Therefore, it is important first to find out what type of pathogens are in your water through a lab test. Depending on the test, you will choose an effective UV filter.

Should Water Be Filtered Before UV Treatment?

It is necessary to treat your water before subjecting it to UV treatment. UV purifiers do not filter out contaminants such as debris, pesticides, and industrial chemicals. The other methods of water filtration are not as effective against microbial germs as UV filters. To strike a reliable balance, combine UV filters with a carbon or whole house filter method for increased effectiveness.

Components of a UV Water Purifier

 UV water filter system explained

A typical UV water purification system will have four main components:

UV Lamp

The primary function of UV lamps is to emit UV radiation. The radiations are calibrated to target and attack all pathogens. The UV bulb contains a filament that radiates a current that is useful in heating mercury vapor. The mercury is contained in small beads found inside the UV lamp. On heating, it evaporates, producing UV rays.

The Reactor Chamber

It houses the UV light bulb. It also controls the flow of water through the UV system. The reactor chamber will determine the size and shape of UV systems.

Quartz Sleeve

This component holds the UV lamp in place. During operation, the UV lamp is surrounded by contaminated water. The quartz sleeves protect the lamp, ensuring ease of access for maintenance and guaranteeing a longer lifespan.

Controller Unit

It acts as the brain of the UV system. Manufacturers embed different functionalities in this unit which determines the overall cost of the system.

When to Use a UV Water Purifier

You can utilize a UV water filter for home consumption or travel. We recommend that you install the UV system at the water point of entry into your home. Private well owners are advised to have the UV filters in place before consuming the water.

For those who travel a lot, especially backpackers or campers, handheld UV water purifiers come in handy. A separate filter (prefilter) eliminates these contaminants for water that comes with dirt and debris.

How Long Does It Take to for UV Light to Kill All Harmful Microorganisms?

A UV water filter system kills pathogens in about 10 seconds. The effectiveness will depend on the distance the UV rays travel to reach the pathogens.

Are Ultraviolet Light Water Filters Safe?

Drinking water purification using UV light is safe. The method has been in use by water utility companies and commercial water bottling companies. Many people are often alarmed by the use of mercury in UV systems. The amount of mercury in the purifier is minuscule and confined, so it cannot contaminate your water.

UV disinfection is an environmentally friendly disinfection method that has been certified by EPA. Due to its effectiveness, UV purifiers are used in water treatment systems by millions to provide safe drinking water.

Advantages and Disadvantages of UV Water Filters

  • Guaranteed effectiveness: UV purification kills bacteria and viruses in water with 99.99% effectiveness.
  • Reliable: You do not have to constantly test your water supply because you are sure the UV purification process is active for at least 9000 hours.
  • Environmentally-friendly: UV water filtration is a great alternative to chlorine-based systems. It does not add any chemicals, wastewater or release any waste products into the environment.
  • Low energy demand: UV water purifiers only need little electricity to complete the water purification process.
  • Inexpensive: Base models do not require a lot in initial investment. For maintenance, you only need to replace the lamp once per year and sleeves after two years.
  • Free from chemicals: UV treatment does not require the use of harmful chemicals to kill bacteria.
  • Rapid treatment of water: UV filters water quickly without affecting the water flow rate. The system does not require a storage tank.
  • A UV filter is only limited to eliminating living microorganisms. The UV system cannot deal with other contaminants such as heavy metals, pesticides, and other harmful chemicals. You need to combine a UV purifier with other processes to eliminate these other contaminants.
  • No change to taste or odor of the water. UV water purifiers do not alter the taste or the odor of the water. You will need to combine your UV water filter with a carbon filter or reverse osmosis system to achieve this.
  • A UV water purifier requires electricity to work. It may not be useful in rural or emergencies.
  • UV disinfection only works in clear waters. If the water is muddied or contains many floating impurities, ultraviolet light will not work against the microbes in the water.

What Do UV Water Systems Remove?

A UV purifier targets and eliminates living microorganisms from your water supply. It guarantees an extremely high percentage (99.99%) killing harmful microorganisms. Some of the common organisms eliminated by UV treatment are:

  • Hepatitis B
  • E. coli
  • Algae and Fungi
  • Mycobacterium tuberculosis
  • Dysentery bacilli
  •  Cryptosporidium Typhoid Fever
  • Salmonella
  • Viruses
  • Giardia
  • Flu

Some of these pathogens are famous for causing life-threatening conditions. It is prudent to install a UV system to protect yourself.

Who Can Use UV Water Filtration Systems?

Some households and regions are more susceptible to having pathogens in their drinking water. These groups will definitely draw more benefits from having a UV water filter.


Families with kids or the elderly benefit greatly from sterilized water. UV filters kill pathogens that negatively impact these age groups.

Populations With Lower Immunity

Immunocompromised individuals are hight recommended consuming sterilized drinking water. With UV water purifiers effectively killing pathogens, these individuals can be assured of virus and bacteria-free water.

Well Owners

Water from the well will likely have these harmful living microorganisms. Installing a UV water purifier goes a long way in dealing with any microbial contamination.

Maintaining a UV System

After installation, a UV water filter does not require constant maintenance. Maintenance will be pegged on the usage rate. Normally, if used throughout, some components have to be replaced yearly.

Replacing the UV lamp

The UV lamp is usually replaced after 375 days of continuous usage. During usage, the mercury vapor continually dissipates. Once the mercury is used up, the system will strain to sterilize your water, leading to a breakdown.

Replacing the quartz sleeve every two to three years. Quartz sleeves lose their transparency after years of usage. It is also prudent to have an extra sleeve in case of damage to the sleeve in use.

Standard UV purifiers come with an alarm. The alarm goes off once the system is unable to kill pathogens effectively. It is a nice feature that reminds users when the filter is no longer effective and the UV lamp requires replacement.


When changing the UV lamp, ensure to clean the quartz sleeve. A dirty quartz sleeve will prevent the effective dissipation of UV radiation.

The Cost of a UV Water Treatment System

As a single unit, a UV purifier will cost between $400 – $1,500. The installation cost for the system will depend on the complexity of the project. Expect to pay from $100 up to $5000 depending on the complexity of the project.

In most cases, households combine UV purifiers with other methods such as undersink to eliminate all contaminants in the water. The combination ensures pathogens and chemical contaminants are all eliminated.

Our Final Thoughts

UV light water disinfection is undeniably an effective way to deal with pathogens. It leaves your water clear of microorganisms that, if left unattended, would result in undesirable health consequences, especially to kids.

UV filters come with a myriad of advantages; however, we recommend that you combine the UV purifier with other methods such as reverse osmosis to eliminate all contaminants. These purifiers are inexpensive and do not require a great deal of maintenance. You can make the installation a DIY project or ask a professional to help.

About the Author

Paul Morton

Paul is a retired plumber who now spends hours on home improvement projects. From fixing toilets to leaking pipes in crawls spaces, there is nothing Paul can't do or wouldn't try. Paul was running his own plumbing company and is our expert in regard to all types of water filtration systems.

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