Long Term Review: SteriPEN Adventurer

In my rather extensive inventory of outdoor goodies, one piece of gear stands out as the most controversial. My SteriPEN Adventurer, almost everywhere it goes, seems to draw suspicious looks if not outright derogatory remarks. The number of people to hastily point a finger at it while saying, “those things don’t work,” blows me away. The reason is simply that––they’re wrong.


The use of UV light to treat water is nothing new, in fact it predates the use of electricity. Early overlanders crossing vast sections of desert would often put water in glass jars, place them in the sun, and let good old daylight work its magic. Hospitals have used UV light to sanitize water and even entire rooms for some time now. Several bottled water companies use it to treat their source water and many large cities like Seatle and New York do the same. It’s proven technology, not that facts are enough to appease some critics.


Back to my little SteriPEN. I’ve had it for a few years now and it has been on dozens of adventures big and small. Not the most current model, mine is the original Adventurer, and at the time I bought it, sold for about $100. The current iteration of my Adventurer is the updated Opti, which now sells for slightly less. More about that later. Lets talk about how these things actually work.




If you hear people talk about how the SteriPEN makes water safe, you often hear people say the light “kills” all the bad bugs in the water. Truth is, it doesn’t kill anything, it effectively scrambles the DNA of said bugs so they can’t reproduce in your system. I am of course talking about things like ecoli, cryptosporidium, giardia, and all the other microorganisms that make people sick. It even does that good work in just 90 seconds.


To use the SteriPEN, the user simply fills a container, no larger than one liter in volume, presses the “on” button, waits for the green light to blink, inserts the SteriPEN bulb in the water, and after 90 seconds the light switches off and the water is now safe to drink. It’s pretty hard to screw up. The original Adventurer I have uses two electrodes on either side of the bulb to confirm the SteriPEN is in water before it turns on the bulb. The new Opti version uses an LED bulb to sense the water before switching on, and that LED bulb can be used as a small flashlight adding another level of convenience to the system.


Here comes my personal endorsement, and something I repeat regularly to the skeptics. I have used my SteriPEN on enough backcountry adventures to have gone through at least eight sets of CR123 batteries. That equates to roughly 800 liters of water. The bulb itself will produce up to 8,000 liters, so it’s quite a value. More importantly, having consumed all that water, I’ve not been afflicted by a bad bug a single time.




There are, as is so often the case, some drawbacks to the system, although I find them to be minor. Treating one liter of water at a time means it is really only for personal or small group usage. Treating large volumes of water isn’t really within the mission scope of the SteriPEN Adventurer. And should the water is nasty to begin with, it will be nasty after it has been treated and made safe to drink. It doesn’t improve the flavor of the water in any way. If your water source has a high degree of sediment and turbidity, that’s what you’re going to be drinking. Speaking to that, it takes a very high level of sediment to make the UV light ineffective. If you don’t want to drink it, chances are the light won’t properly neutralize the microorganisms in the water.


Perhaps my favorite use of the SteriPEN has been for travel in less than clean parts of the world where water is suspect. I’ve even treated water in a glass on my table at a restaurant. I just put the SteriPEN in the glass, gave the water a quick zap, and down the hatch. Try breaking out your whole water filtration pump at dinner to do that.


It’s one of my favorite backcountry tools. When used in the proper setting, it’s darn hard to beat. As you read this, it’s probably in my pocket as I travel through Ecuador and Colombia.



Christophe Noel is a journalist from Prescott, Arizona. Born into a family of backcountry enthusiasts, Christophe grew up backpacking the mountains and deserts of the American West. An avid cyclist and bikepacker, he also has a passion for motorcycles, travel, food and overlanding.