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SteriPEN Ultra Review (with Lab Test Results) South America

Traveling and want to avoid diarrhea? Of course you do. The first thing to do is find safe water. In this post, you’ll learn about a lab test I ran to see how well Steripen sterilizes dirty water. Lets do this!

steripen review lab results

SteriPEN Ultra Review (with Lab Test Results)

Travelers Rule #1: Don’t drink the water!

Everyone knows about travelers’ diarrheaIt is one of the most common and most embarrassing travel-related illnesses. Between 30% to 70% of travelers are affected, depending on the destination and season.

Bad water can cause even more serious problems than a couple of days of diarrhea. Certain amoebas and parasites can only be treated with very strong medication.

But what are you supposed to do? Bottled water is okay as long as it’s available. But what if there are no stores nearby? And buying water can get expensive.

Before we moved to Ecuador, we looked into water filtration and sterilization methods. At home, we use a counter-top water filter. Read our review.

Does SteriPen Actually Make Water Safe?

After writing about boiling drinking water and how to stay safe, SteriPEN contacted us and asked us to test and review one of their UV sterilizing units for travelers.

The model they sent us to test was the SteriPEN Ultra (with USB charging).
We had two options to test the UV light:

  1. Use the pen, drink the water, and see if we get sick
  2. Test the results in a lab

While option #1 sounds tempting, we decided on option #2. Here’s what we did.

How We Tested the SteriPEN Ultra

To find out if it really worked, we took water samples  from two unlikely places (both in Cuenca, Ecuador):

  • a public washroom in a busy shopping center
  • the Tomebamba River (one of the four rivers that run through the city)

We then tested them in a lab. Here’s what we found.

  • The tap water passed the test without treatment. While it did have some bacteria, it was safe to drink. This is impressive, given that we took the sample from a public washroom. As you will see in the video below, I did let the water run for a few seconds first and we used a sterilized container.
  • The river water, of course, was full of life – and dangerous to consume. In addition to a lot of rotting organic material we found bacteria, amoebas, amoeba eggs, and parasite eggs.

Here are photos of some of the wildlife from the river water:

amoeba steripen water
live amoeba steripen water
Once we established that the river water was unsafe, we then we treated the same water with the SteriPEN Ultra and retested the water.

Did The SteriPEN Work? Our SteriPEN Review

Yes. All the life, including amoebas, parasites and bacteria were killed by the SteriPEN and it was safe to drink. It was even safer than the treated/filtered tap water in the same city because everything was dead – including the bacteria.

I should mention that I didn’t stir the unit properly in the test. I was supposed to keep it in motion during the test to ensure uniform purification – but I forgot. In spite of that, it still eliminated all of the living contaminants in the water.

See the end of the post for more tips on proper use.

Here are two image of the same amoeba:

amoeba steripen water

BEFORE: This amoeba is alive. It was taken from the untreated river water. Its movements could be seen on the microscope.

dead amoeba steripen water

AFTER: This is the same type of amoeba, now dead from the UV light treatment of the SteriPEN Ultra.I was really impressed by this test. Seeing the same organism alive and then dead from the UV light convinced me.

We are going to use the SteriPEN on all questionable water from now on.

SteriPEN Ultra Review with Lab Results

Curious about what comes in the box? Here’s what to expect:

Steripen Unboxing Video

SteriPEN Ultra Features

Here are some of the key features of the model we tested:

  • Works in 48 seconds (500 ml) or 90 seconds (1 liter)
  • Treats up to 8,000 liters (over 7 years of safe drinking water for one person)
  • Destroys 99.9999% of bacteria, 99.99% of viruses, 99.9% of protozoa
  • USB rechargeable from a computer, wall socket or solar panel

It is quite fool-proof: The Ultra model displays a smiley face when you have successfully treated the water and it won’t turn on unless it is properly submerged in the water.

9 Tips for Safely Using the SteriPEN

Here are a few things to keep in mind as you get started with the SteriPEN:

  1. The unit should be moved in a stirring motion during water treatment. This agitation helps ensure consistent purification.
  2. SteriPEN is meant for use in clear water. It can be used to treat turbid or cloudy water in an emergency. It is always best to physically filter the water to remove as much dirt and silt as possible. This material will affect the effectiveness of the UV light. SteriPEN recommends doubling the treatment time on cloudy water.
  3. The UV lamp emits both visible and UV light. If the lamp isn’t emitting visible light it needs to be repaired or replaced.
  4. The UV light will not treat water droplets on the mouth of the water bottle. Always be sure that the mouth of your bottle is clean and dry before drinking purified water.
  5. Because glass, plastic, ceramic and metal all absorb or reflect UV light, you are not at risk for UV exposure.
  6. Do not use in water above 120°F / 49°C
  7. A fully charged SteriPEN can treat approximately 50 liters of water. Always charge your unit before heading out.
  8. The OLED  screen will indicate when the bulb is nearing it’s end – displaying when it has less than 100 treatments left.
  9. The unit has two water-sensing pins. They must be submerged in the water in order for the light to turn on.

3 More Reasons to Use SteriPEN

SteriPEN not only keeps you healthy. There are other key benefits.

  1. Save Money: Let’s do a little math. One SteriPEN will purify 8000 liters of water. That means you won’t buy 16,000 bottles of water. Even here in Ecuador where water is cheap ($0.30/500ml bottle) this would save you $4800 for the life of the purifier. Water can cost between $0.03 and $3.00 for a 500ml bottle. At less than $100, the SteriPEN makes good economic sense.
  2. Save Time: Water isn’t always available. Who wants to spend time your travel time looking for a bottle of water? Just take some tap water, treat it and enjoy your travels.
  3. Save the Environment: Beside the costs of buying water, there is also the environmental impact of thousands of bottles of water. By purifying 8,000 liters of water (the life of a SteriPEN) you are keeping 16,000 bottles out of the landfills.

steripen review lab results
Note: While we were given a free unit to test and review we didn’t receive payment for this review. The thoughts and opinions are our own. The links to SteriPEN in this post are affiliate links. If you purchase this product we will make a small commission. You will pay the same either way.

Contest: How will you use your Steripen? (Contest closed)

Tell us how (or where) you will use the Steripen Ultra and you might win it! Have a trip planned? Where are you going? Why do you need water sterilization? How will you use your SteriPEN Ultra? Tell us all about it in the comment section below and our favorite comment will receive the SteriPEN Ultra (the same model we tested and reviewed in this post) direct from SteriPEN. Contest closes September 6th, 2014 at 12 noon (GMT-5, Ecuador time). The winner will be contacted directly and published here on this post. Contest is sponsored by SteriPEN.

(Update, September 9, 2014) The contest has closed and the winner has been chosen. Congrats to Leire Pacheco who is heading out on a round-the-world trip in two months. The SteriPEN is going to come in handy! Read Leire’s comment.

cuenca water quality

Water Safety in Cuenca

After publishing about our water filter two years ago, we learned that water quality is a hot topic among expats. There are almost one hundred comments on that post – showing how important this is for everyone.

For the test, we took water samples from two locations:

  1. tap water from a public washroom
  2. the Tomebamba River

I know, what were we thinking? Well, two things. First, we wanted to avoid taking water from a building that had a secondary filter. We wanted to get true Cuenca water – so we took it from a non-residential area. And secondly, we wanted some really dirty water to see how well the SteriPEN actually worked. The river water worked well for this.

Cuenca Water Lab Results

What were the results?

  • Cuenca’s tap water: PASSED, even though it came from a public washroom. There were some bacteria, but it was free of amoeba and parasites. The lab technician said that it was safe to consume.
  • Cuenca’s river water: FAILED. Not surprising, the river water was a dangerous mix of parasite eggs, amoebas, and bacteria. The technician said it looked like a zoo of microscopic activity.

Here are some of the critters we saw in the water:
parasite cuenca ecuador

cuenca water quality

Before water treatment

drink cuenca water

Same organism as above, but after sterilization: Dead

pH Levels of Cuenca’s Water

In addition to contaminant tests, we also tested pH levels of both types of water. Cuenca’s tap water had a pH of 7 (neither alkaline nor acidic) and the river water had a pH of 8 (moderately alkaline).

The SteriPEN treatment didn’t change the pH level. A pH level of 7 is considered perfect for drinking water.

SteriPEN Sterilization Results

We initially planned to use the SteriPEN to sterilize both water samples but because the tap water came back safe, we didn’t bother.

We did treat the river water and then we re-tested. This was very interesting.

During the initial test, we saw live amoebas and parasite eggs. After sterilizing the water with the UV light, they were all dead. We saw the same organisms but they had been killed by the light.

Note: the UV light in the SteriPEN will kill living organisms in the water, but it doesn’t filter the water. Although the dead organisms remain in the water, they won’t do any harm.

So, the SteriPEN was able to take dangerous water and make it safe to consume.

chart of common ecuador parasites

Chart of Common Human Parasites in Ecuador

Does This Mean All Ecuador Water is Safe?

Can you drink all the water in Ecuador? Of course not. The technician noted that he has tested the water in some small towns just outside of Cuenca and they are unsafe and will cause sickness. He told me that he uses a water filter system in his home.

While we will continue to occasionally drink the water in Cuenca, we prefer to filter all of our water at home. We use a counter-top ceramic filter for an extra level of security to keep us healthy. When we lived in Canada, we drank our well water – but only after running it through a ceramic and sediment filter. It is inexpensive and worth the trouble to stay healthy.

Other expats in Cuenca don’t filter the water and don’t have have trouble with sickness. It really is a preference / confidence issue.

When would you use a SteriPEN? It is ideal if you are either living outside of Cuenca and/or planning to travel around the country or more of South America.

Now, it’s your turn

Have you used a SteriPEN? How do you stay healthy abroad? Please share your thoughts and tips below…

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Thursday 6th of October 2022

[…] According to Steripen, each treatment “destroys over 99.9% of bacteria, viruses, and protozoa”. A few years ago, I ran a lab test to see how well it works – here are the results. […]


Sunday 1st of March 2020

This is now a long time after this interesting experiment was done, but it remains a commonly-used purification system. I am interested in using it myself, but one thing bothers me, and that is the area above the unit that is not sterilized. You were obviously aware of that, as you wrote: "The UV light will not treat water droplets on the mouth of the water bottle. Always be sure that the mouth of your bottle is clean and dry before drinking purified water." I cannot imagine that simply drying the contaminated area would be of much use to prevent re-contamination. When the technicians sampled the sterilized water in your test, did they pour it out past this contaminated area, or bypass it with a sampling pipette? It seems to me that this contamination issue with this system is a negative....what are your thoughts?

Daniel Soebbing

Tuesday 8th of December 2015

Thanks for reviewing the Steripen. While I find your inquisitiveness and curiosity about the functioning of this device to be admirable, I don't think your experiment was very scientific. For one, the majority of the organisms of which you have posted images are diatoms and other types of phytoplankton, not pathogens. The "After" image is definitely a diatom, while the "Before" image is difficult to identify, due to image quality. There was definitely an amoeba swimming around in the video that you posted. But I don't see any evidence of dead amoebas. While I have no doubt that the Steripen is capable of rendering most pathogens uninfective, the type of test that you conducted is not a good way of determining this. A true measure of the effectiveness of this device would require a study that can determine if organisms are capable of reproduction post treatment. Simply looking in a microscope to see if organisms are moving around after being zapped by UV light doesn't really tell you anything. A lot of pathogens, such as Cryptosporidium parvum oocysts, and viruses, won't be seen to be swimming around under a microscope, even when they are alive. But that doesn't mean that they can't cause an infection! I think there is a lot of evidence that the Steripen is a trustworthy device. But I think there are better sources of evidence out there.

Bryan Haines

Tuesday 29th of December 2015

While I find your condescending comment entertaining, I don't think your response was very well researched. The effect of UV light on microorganisms is well documented. While I was there for the test, a trained lab technician oversaw it. He observed the life before and the absence of life afterward. That was the purpose of the test and it passed. You are correct, the image quality isn't that good. That is my fault - I was trying to take a photo through the microscope with a point and shoot camera. But my bad photos don't negate the technicians findings. If you doubt these results - or that the Steripen works at all - I invite you to run your own test, hire a lab and share your results here.

You Can Drink the Water with SteriPEN – Southern Boulder

Friday 31st of October 2014

[…] Source: SteriPEN Ultra Review (w/ Lab Test Results) South America […]


Wednesday 24th of September 2014

Thanks for the information. I am moving to Cuenca November 1st and while everything I've read indicates that the Cuenca water is good to drink, a little insurance can't help. I've ordered the SteriPen and will make good use of it. For the areas outside of Cuenca, I can only hope it works as well as yours did for the test. Thanks for the info.