Cryptosporidium UV Water Treatment – What You Need to Know

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Although it’s not a pleasant topic to think about, homeowners should be aware their drinking water might contain microorganisms like cryptosporidium that may cause health issues.

One of the best ways to prevent this from happening to you is to add a UV water purifier to your plumbing system.

Along with pre-filtration, UV rays can purify your water and minimize your chances of being infected with cryptosporidium.

Key Takeaways

  • Cryptosporidium (crypto) is a microorganism that an infected person or animal will shed through their feces.
  • Crypto can enter your home’s drinking water and cause such symptoms as watery diarrhea if you consume it.
  • When combined with a pre-filtration system, UV water treatment can effectively kill 99.99% of crypto in your drinking water, limiting the risk of infection.

About Cryptosporidium in Drinking Water

Several types of microorganisms have the potential to enter your drinking water. Exposure to or consumption of contaminated water can result in health problems.

Cryptosporidium is one such microorganism that may lead to unpleasant symptoms if you drink it via your home’s water.

Giardia lamblia parasite

How Is Crypto Spread?

An animal or person infected with crypto may spread it via their stool. Cryptosporidium has an outer shell which allows it to survive in harsh environments for long periods of time.

Because animals and people may spread crypto through their feces, it can sometimes make its way into water sources and soil. The risk of exposure to crypto may thus be higher if you’re consuming water from sources near grazing areas. Along with agricultural runoff, other ways crypto can enter your home’s drinking water include:

  • Sewage overflows
  • Improperly working sewage systems
  • Runoff from storm water

Symptoms of Infection

Cryptosporidium infection is rarely life-threatening unless an individual has a highly compromised immune system or other such condition. However, it can be very uncomfortable.

Symptoms of crypto infection tend to become noticeable between as early as 2 days after infection and as late as 10 days. The most common symptom of crypto infection is watery diarrhea. Additional symptoms include:

  • Vomiting
  • Stomach cramps
  • Weight loss
  • Nausea
  • Fever
  • Dehydration

Most people will experience symptoms for 1 to 2 weeks. However, some experience symptoms for as long as 4 weeks, while others may experience no symptoms whatsoever.

Sometimes, symptoms will lessen only to return or even get worse. If you suspect you’ve been infected with crypto, see a doctor right away. Again, although the infection may eventually resolve itself, it could potentially result in a more serious health issue if you have a chronic condition or a weakened immune system. It’s best to err on the side of caution and seek medical attention.

Cryptosporidium UV Water Treatment

Equipping your home plumbing system with a UV water treatment solution is a smart way to guard against exposure to crypto via your household drinking water. This option is both safe and effective because it doesn’t use chemicals to kill microorganisms. That’s important, as crypto is resistant to chlorine-based disinfectants.


A UV water purifier is usually the final purification step in a water treatment system. Although it works efficiently by killing microorganisms in your water as the water runs through a main chamber where it’s exposed to UV light, its efficiency is optimized when water has been pre-filtered before reaching the UV purifier.

Microorganisms in your water also don’t need to be exposed to UV light for very long for the rays to kill them. A brief exposure is all that’s necessary, ensuring your UV purifier can do its job quickly.


Various factors can influence a UV water treatment solution’s reliability. They include the following:

  • Pre-filtration: Particles suspended in water can block UV rays and prevent them from killing microorganisms. It’s therefore important that water be pre-filtered before it reaches a UV purifier. In addition, UV purifiers kill microorganisms like crypto, but they don’t actually remove any materials from your water. This is another reason to combine a UV water treatment solution with other filtration/purification equipment.
  • Maintenance: To work as effectively as possible, a UV water filter needs to be installed properly and maintained regularly. Specifically, you need to ensure the UV water purifier’s quartz glass sleeve remains as clear as possible so the UV rays can penetrate it. Achieve this by regularly cleaning and replacing the quartz glass sleeve. You may need to clean or replace the glass sleeve more often than you otherwise would if you have hard water, as hard water can cause the sleeve to fog up.
  • Power: A UV water purifier can only disinfect your water if it’s connected to a working power source. It won’t serve its purpose during a power outage.

Luckily, a UV water treatment system can be highly reliable when it’s installed properly, regularly maintained, combined with pre-filtration, and connected to a power source, delivering up to a 99.9999% disinfection rate.

young woman drinking water

How Does UV Light Kill Cryptosporidium and Other Microorganisms?

A typical household UV water purifier will consist of the following main components:

  • UV lamp
  • Quartz glass sleeve
  • Main chamber
  • Control unit

The quartz glass sleeve surrounds the UV light bulb. The bulb (or lamp) itself runs the purification system’s full length and radiates UV light in all directions. The sleeve is made of quartz instead of other types of glass because it provides for high UV light transmittance.

A large encasing chamber (sometimes referred to as the reactor chamber) surrounds the quartz sleeve. Each end of the main chamber features connecting seals which allow it to easily connect to most home plumbing networks.

Water flows into the main chamber where UV light shines on it from all sides. This UV light kills crypto and other harmful microorganisms (although it doesn’t technically remove their bodies from the water). It does so by essentially “scrambling” the DNA of said microorganisms. It also does so safely, purifying the water without any risk of harmful effects to those using or consuming it.

A UV water purifier’s control unit allows a homeowner to manage the UV bulb’s operation.

If you have any questions about cryptosporidium UV water treatment please don’t hesitate to leave a comment below!

About the Author Gene Fitzgerald

Gene Fitzgerald is one of the founders of BOS and currently head of content creation. She has 8+ years of experience as a water treatment specialist under her belt making her our senior scientist. Outside of BOS, Gene loves reading books on philosophy & social issues, making music, and hiking.
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