UV Water Purification Advantages and Disadvantages

Author: Rory Mullan - Published: 2022/05/25 - Updated: 2022/12/22

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When it comes to keeping your water free from microbial contamination, UV water purifiers are one of the most effective methods out there. These systems come with a lot of different advantages such as cost-effectiveness. However, they are not without their drawbacks.

If you’ve been considering installing a UV filtration system, comparing its pros and cons is a good way to know if they are a good fit for you.

In this article, we’ll break down all of the advantages and disadvantages of UV water purifiers, so you can make an informed decision on whether to use one or not.

So, here is our guide on the pros and cons of UV water purification.


UV water purifier benefits:

  • Highly effective at disinfecting water
  • Chemical-free (do not influence water flavor and smell)
  • Economical and energy-efficient
  • Eco-friendly
  • Simple to set up
  • Easy maintenance
  • Compact

UV water purifier drawbacks:

  • Don’t remove contaminants
  • No enhancement to water aesthetics
  • Needs ongoing power supply
  • In water with suspended particles/hardness, effectiveness is reduced
  • Stagnant water may come out warm

How Do UV Water Purifiers Work?

To understand the pros and cons of a UV water purifier, we first have to know what they are and how they work. UV water purifiers or filters use ultraviolet light to kill microorganisms in the water. They do this by scrambling their DNA. They don’t, however, remove these organisms from the water. They just render them harmless.

A UV water purifier uses a UV lamp encased inside a quartz glass sleeve. The sleeve is located inside the chamber where the water runs through, so that the light can do its job.

Advantages of a UV Water Purifier

UV Water Purification Advantages and Disadvantages thumbnail

Using a UV system to kill microorganisms in your water comes with a lot of benefits, these include:

Effective Disinfection

When properly used and supported, most UV water purification units can kill up to 99.999% of the microorganism commonly found in water. That’s an effectiveness rate that few other methods can match. However, it should be noted that this level of effectiveness often requires some pre-filtration of the water supply.

No Wait Time for Purification

With UV water purifiers, there’s no delay or wait for the system to do its thing. Your water is already purified the moment it comes out. At most, you’ll be waiting for the same amount of time you would for water to come out of any faucet normally.

Doesn’t Use Chemicals nor Affect Water Taste or Odor

Since UV purifiers only use light, there are no residues left in the water or any other effects.

Furthermore, your water never comes in contact with anything that could affect its taste, smell or composition. The water only ever comes in contact with the chamber and the quartz sleeve. It will be essentially the same water before and after being disinfected.

Approved By the FDA

UV water purifiers are one of the water purification methods that are actually approved by the FDA[1]. If you only trust systems that have gone through the wringer as far as rigorous testing goes, this is the one for you.

Energy Efficient and Cost Effective

UV purifiers are one of the most energy-efficient filtering methods out there. That’s because their main use of energy comes from the UV lamp, which is not that different in terms of power consumption from a regular house lamp. They don’t use water pumps, fans or other components that could draw power.

On top of that, they don’t require expensive maintenance. If properly maintained, you should only need to replace the quartz sleeve and UV lamp about once every year or two. That would be the only significant maintenance cost.


UV purifiers don’t produce additional waste, use little energy, and don’t leave any residues in water. This makes them a more environmentally friendly option for water purification than most alternatives.

Easy to Use

A UV water purifier doesn’t have complex mechanisms or a difficult control method. It’s just water flowing through a chamber. No moving parts that could break or get stuck. This also reduces the amount of maintenance needed, only having to clean it every once in a while.

Compact Design

Unlike some other types of systems, UV water filters take up very little space inside your house. You don’t need to make any changes to your house’s plumbing or layout either. They can fit just about any home.

Doesn’t Corrode or Damage Your Pipes

Some water purification methods can cause your pipes to corrode over time due to the use of chemicals. With a UV filter, the only thing that will touch your pipes is water.

Disadvantages of UV Water Disinfection

Unfortunately, it isn’t all perfect. UV water purifiers do have some drawbacks, which include:

Can’t Expel Contaminants from Water

UV water filters are great at neutralizing microorganisms, but they don’t actually remove them. The same applies to other particles that could be in the water. That means that without a supporting system to filter out these contaminants, they’ll continue to be in the water. While they are harmless to you, the buildup can affect the UV system if left unchecked for a long time.

Performance is Greatly Affected by Water Hardness and Other Conditions

inspecting water sample with magnifying glass

The purity and hardness of the water have a direct impact on the performance of your filtration system. Hard water has a lot of minerals in it, which if not filtered through other means can block the UV lamp’s effectiveness. It can also lead to more frequent replacements of the quartz glass due to extra residue.

This can be offset through the use of water softening and filtering systems.

Difficult to Inspect

We can’t see UV light, as it’s invisible to the naked eye. This makes it difficult to tell whether your UV light is on or not just by looking at it. Furthermore, if you need to check the glass sleeve for scratches you have to take out the entire lamp, which is fragile and could break or scratch easily.

Doesn’t Improve Water Taste or Smell

UV filters don’t affect your water’s taste or smell at all, which is a sword that cuts both ways. It won’t make your water smell or taste differently, but if it already tasted bad or smelled weird it won’t do anything to improve it either. This is because UV purifiers don’t affect the type of pollutants that typically cause water to taste or smell bad.

In such cases, you would need additional filtering systems.

Needs Power to Work

UV purifiers use a lamp to do their job, so if the power goes out so does the lamp. However, this would only affect the purification of the water, not its flow. Water will continue to pass through the unit without any issues.

Can’t Store Water within a Tank

UV purifier systems don’t come with an integrated tank to store the water. If you want to store a lot of water, you’ll have to use your own means. To some, this could be a pro, as stored water that has been sitting for a while isn’t exactly fresh.

Might Heat Up Water Slightly

This one is a very minor issue, but still worth pointing out. The UV lamp emits some heat which is absorbed by the water. Normally, this isn’t enough to affect its temperature to a noticeable degree. However, if you haven’t used water in your home for a while, you might notice it coming out warmer when turning on the shower or opening a faucet.


UV water purifiers are one of the most effective and reliable purification methods out there.

They are easy to use and maintain and use very little power.

On the other hand, they do require support from other systems to properly expulse contaminants from water and won’t do much to improve its taste or smell.

Ultimately, we feel that the benefits far outweigh the downsides, but we leave the final judgment to you.

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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