Is a UV Water Filter Necessary? When Do I Need One?

Author: Rory Mullan - Published: 2022/09/09 - Updated: 2022/12/22

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Whether you are drawing your water from a municipal water source, or you have your own private well, chances are you’ll have to deal with some form of contamination.

For example, it could be algae, bacteria, or other microorganisms. Regardless of the exact type, it will be a problem you’ll want to take care of.

One of the best ways to do so is by using a water filter system that’s designed to kill any living pathogens, like a UV water purifier.

In this article, we’ll discuss the use of UV water purifiers, their benefits and drawbacks, and when you should consider installing one.

So, here is our guide on the question, do I need a UV water filter?


  • UV water filters are highly effective at disinfecting and eliminating harmful microorganisms such as viruses and bacteria in your water.
  • Investing in a UV water filter system is advisable for most households as this ensures that they have access to drinking water free of harmful microbes.

Do I Need a UV Water Filter?

Do I Need a UV Water Filter thumbnail

Water flowing out of the taps in our homes has, in many cases, been revealed to hold bacteria such as E. coli and other microbes, particularly in the case of private well water.

The best way to deal with such type of problem is by using a UV water purifier. A UV water treatment system can kill up to 99.9999% of harmful germs in the water, making it the best option for treating your water for microbial contaminants.

Do I Need a UV Purifier for City Water?

Although municipal water suppliers must observe certain safety requirements[1], water can take up germs and other diseases once it exits the treatment facility.

Besides, a UV water purifier is one of your best options in a natural disaster or if you suspect your water contains hazardous microorganisms due to any other reason.

What is a UV Water Filter and How Does it Work?

UV water disinfection lamps emit a certain wavelength of light: 254 nanometers, which is effective for killing germs. As such, UV light rays can break down the DNA of bacteria, viruses, cysts, algae and fungi.

Living organisms in the water are exposed to UV radiation during the treatment process, which damages their genetic code (DNA/RNA), rendering them unable to function and reproduce.

If a microorganism is unable to proliferate, it is unable to infect other species with which it comes into contact. So without chemicals, UV light can eradicate up to 99.9999% of dangerous germs in water.

Contaminant Reduction

UV water treatment targets a wide range of infectious pathogens, including:

  • coli
  • Vibrio cholerae
  • Typhi salmonella
  • Shigella sonnei
  • Cryptosporidium cysts
  • Giardia cysts
  • Hepatitis A virus
  • Type 1 poliovirus
  • Rotavirus


A UV system is made up of four primary components:

  1. UV Controller: The UV ballast or control unit is the brain of any UV system. Some UV systems employ a simple controller, while others employ a more complicated device with alarms, lamp change timers, warning lights, etc. Regardless of the size or complexity of the UV unit, all controllers accomplish the same thing: they control the lamp output and power the UV-C light required for water purification.
  2. UV Chamber: This component holds the UV sleeve and light bulb and regulates water flow.
  3. UV Lamp: A germicidal UV-C light is emitted by a UV lamp (bulb). Because different lights serve different duties, the application and disinfection requirements will determine the specific type of lamp utilized.
  4. Quartz Glass Sleeve: The quartz sleeve of a UV system is a long, cylindrical tube. The UV lamp is shielded by this quartz glass tube. Through the tubes, UV light is emitted into the water.

The Benefits and Drawbacks of UV Water Purification

While UV water treatment is quite successful at removing microbes from your water source, it is not a complete solution. It has advantages and disadvantages, just like any other water treatment method.

Here are the benefits and drawbacks of using UV light to treat your water:

Benefits of UV Water Treatment

  • UV therapy saves previous electricity because it utilizes about the same wattage as a conventional light bulb.
  • Because UV light is the only element employed, no chemical treatment is required. Your water’s color, taste and smell remain unchanged.
  • Because the purification procedure is short, you can drink clean water immediately. A storage tank or reaction delay is not required with such a system.
  • The only maintenance required is a light bulb replacement once a year and changing the quartz sleeve every other year. No filthy parts need to be disposed of.
  • Effective against up to 99.9999% of viruses and bacteria in water.
  • Because it creates no byproducts, UV disinfection is more environmentally friendly than chlorine disinfection.
  • It is reliable; it operates 24 hours a day, seven days a week, keeping your water safe (you will not need to test your water frequently).
  • When compared to chlorine or chloramine, UV water treatment is especially efficient against some aquatic cysts.
  • Produces no wastewater.

Drawbacks of UV Water Treatment

  • Because system operation requires electricity, access to an electrical supply must be nearby. If power fails or is absent, clean water is inaccessible.
  • Although UV filters destroy germs, they do not eliminate other water pollutants such as rust, pesticides, fluoride, or arsenic.
  • UV light disinfection requires clear water to work. A pre-filter should be used when the water is murky or contains floating particles. When other particles block UV radiation, it cannot reach the microbes.
  • The water tastes and smells the same after treatment. You will need to install additional filtration if you want to improve the taste and smell of your water.

Is it Safe to Use a UV Water Purifier?

bacteria under microscope

When used correctly, UV purifiers are completely safe and effective. They should only be used in clear or slightly cloudy water, though, unless instructed by the manufacturer.

The light must be able to enter the confined water to kill all germs. UV light cannot penetrate and reach all microorganisms in muddy or murky water. In these cases, a different type of filter or the inclusion of pre-filters is advised.

When Should You Use a UV Water Purifier?

A UV system should be installed if you are concerned about microbial contamination in your drinking water.

A failed water test typically initiates a person’s trip into water filtration, particularly if they reside in a rural region. Water tests may reveal the presence of coliform bacteria such as E. coli.[2] Any laboratory that analyzes water can find harmful germs like these. You must act soon once they have been recognized.

Chlorine is a strong oxidant. When introduced into water, it is toxic to bacteria and other pathogens. The problem is that chlorine reacts with some of the naturally occurring compounds in water, producing toxic byproducts that should be avoided when drinking water.

On the other hand, UV has no effect on the quality of the water. Any germs are simply eliminated as they pass under UV light. However, UV light therapy is unsuccessful at eliminating water pollutants or enhancing the taste or odor of water, which is not its intended application.

Reasons Why You Shouldn’t Use a UV Water Purifier

While UV purifiers are a wonderful choice, they are not ideal systems and have scenarios when they are not the best option. Consider the following reasons why you might not want to use a UV purifier:

  • While a UV water purifier removes bacteria, viruses, and other living organisms that could harm you, all other impurities remain.
  • UV water purifiers disinfect and make potable water safe to consume. On the other hand, water that is excessively unclean cannot be treated. Only use a UV filter after the water has been thoroughly cleaned of sediments and other impurities. As a result, there may be an additional cost that comes with UV water purification.
  • In the event of a power loss, you will be unable to access disinfected water.
  • A UV water purifier’s operation is invisible to the naked eye. As a result, if you don’t realize the cleaner has ceased operating, you may drink tainted or untreated water.


UV water purifiers are the best way to deal with bacteria, microbes, and other organic contaminants in water. So if this is a problem that you’re facing, then yes, you do need a UV water filter.

Since there are no chemicals involved in the purification process, your water will come out clean and safe to drink and without any strange odors, unless they were there in the first place.

One of the drawbacks of this process is that it won’t make your water taste or smell better.

Further Reading


Meet Rory Mullan

Rory Mullan Rory has joined the Water Masterz team as a contributing writer. He has covered all sorts of topics in the last several years.

Outside of his writing work, Rory enjoys photographing the Irish landscape and making music!

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