Do I Need UV Light for Well Water? Find Out Here!

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Treating private well water is important if you want to minimize any health risks associated with it.

Normally, this involves a series of water treatment solutions, like filters and softeners. The exact combination appropriate for your situation will mainly depend on the types of contaminants you’re dealing with in your water supply. This article focuses on UV light.

So, do you need UV light for your well water?

Key Takeaways

  • Treating your well water thoroughly is important no matter what type of well you’re using. Using a UV filter is highly recommended.

Do I Need UV Light for Well Water?

Yes. using a UV water purifier is recommended for water sourced from a well. Even if you don’t have a high level of bacteria and other microorganisms present right now, this might change in the future. It’s good to be prepared in advance.

When to Use a UV Water Purifier

A UV water purifier is specifically designed to kill waterborne pathogens by scrambling their DNA. It’s a very effective water purification method in cases of biological contamination.

However, it’s completely ineffective at dealing with other types of contaminants. In fact, the effectiveness of a UV water purifier may be reduced if the water passing through it is not filtered by other means beforehand.

UV Well Water Treatment Considerations

To understand the situation with your water supply and identify the most appropriate types of purification to use, you should start by getting your water tested. This will give you a clear overview of the types of contaminants present, and it will allow you to make a sound decision when investing in the various water treatment options.

UV Pretreatment Needs

As great as UV water purifiers are, they only work well under specific conditions. In order for a UV purifier to operate properly, your water should meet the following criteria:

  • Hardness < 7 gpg
  • Iron < 0.3 ppm
  • Manganese < 0.05 ppm
  • Turbidity < 1 NTU
  • Tannins < 0.1 ppm
  • UV Transmittance > 75%

If your water supply doesn’t meet the full list of parameters, you’ll need to address any deficiencies first. This is usually done by treating the water with specific methods – for example, an iron filter can remove iron and manganese, while a sediment filter can improve the water’s turbidity. A tannin filter, as the name implies, is used for dealing with tannins.

replacing dirty whole house sediment filter

UV Water Disinfection vs Shocking a Well

Shock chlorination involves introducing a large amount of chlorine to your water supply to kill most bacteria present in it. It’s a cheap and effective approach, but it has some limitations. Most notably, it’s only a temporary fix that doesn’t resolve your contamination issues in the long run. It’s also not the most reliable treatment option.

On the other hand, UV water purification can work much better in the long term. If you are concerned with keeping certain biological contaminants out of your water supply for good, you should definitely consider investing in a UV purifier.

Advantages and Disadvantages of UV Water Purification


  • Very effective at dealing with bacteria, viruses, cysts, and other germs
  • Doesn’t use any chemicals
  • No physical contact with the water
  • Easy to maintain
  • Doesn’t damage your plumbing


  • Doesn’t work for other types of contaminants except those mentioned above
  • Requires pre-filtration in most cases
  • Requires constant power supply
  • Doesn’t improve taste or smell of well water

What’s a UV Water Purifier Anyway, and How Does It Work?

A UV water purifier is a relatively simple device, despite looking complicated to someone who’s never used one before. Its operation is based on the fact that UV light is deadly to microorganisms. Even brief exposure to UV light is enough to destroy most bacteria for example.

As long as the water is properly filtered and doesn’t contain anything that could block the UV rays, UV water disinfection is a great approach.


  • Reactor chamber: this is the main housing of a UV water purifier. It’s typically made of stainless steel, though in some cases alternative materials could be used. This is a large tube which contains the main purification unit. All water passes through the chamber and is exposed to UV light inside it.
  • UV lamp: in the middle of the reactor chamber, a UV lamp constantly emits UV light in all directions. As water runs through the chamber, it passes by the UV lamp and is exposed to the light emitted by it.
  • Quartz sleeve: UV water purifiers don’t use regular glass for the housing of the UV lamp. Instead, they use quartz glass, as it has much better properties for allowing UV light to pass through. The quartz sleeve is designed to separate the UV lamp from the surrounding water, while allowing light to pass through almost uninhibited.
  • Control unit: this controls the operation of the UV water purifier. It may have additional features like alerting you when the lamp needs to be replaced or triggering an alarm if anything goes wrong with the filter.

What’s Being Removed

UV water purifiers work exclusively on certain types of microorganisms. This includes most types of bacteria. If you’re dealing with biological contaminants like bacteria and viruses, it’s highly recommended to use a UV purifier in your setup.

Unfortunately, a UV water purifier won’t remove anything else. Not only that, but it will not work as well if you don’t treat your water for other types of contaminants before it reaches the UV system.

If you have any thoughts about the question, do I need UV light for well water, please don’t hesitate to leave a comment below!

About the Author Alexandra Uta

Alex is a content writer with an affinity for research and a methodical attention to detail. Since 2020, she has fully immersed herself into the home water treatment industry only to become an expert herself. Alex has been using water filters and similar products for years which has gained her lots of hands-on experience.
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