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Reviews > Water Treatment > Ultraviolet > SteriPEN Adventurer Opti > Test Report by Andrea Murland

SteriPEN AdventurerOpti
Test Series by Andrea Murland

Initial Report - May 18, 2010
Field Report - August 3, 2010
Long Term Report - September 28, 2010
Addendum - August 27, 2017

Tester Information

Name: Andrea Murland
Email: amurland AT shaw DOT ca
Age: 24
Location: Rossland, British Columbia, Canada
Gender: Female
Height: 5 ft 2 in (1.57 m)
Weight: 125 lb (57 kg)

I began hiking frequently in 2006 and have since hiked in Western Canada, Australia, and spent 2 months backpacking in the Alps. I spend most weekends either day-hiking or on 2-3 day backpacking trips, with some longer trips when I can manage them. I also snowshoe and ski in the winter, but don’t have a lot of experience with winter in the backcountry yet. Elevation is typically 500-3,000 m (1,600-10,000 ft), in the Canadian Rockies and the Selkirk, Purcell, and Monashee ranges. I try for a light pack, but I don’t consider myself a lightweight backpacker.

Initial Report – May 18, 2010

Product Information

Manufacturer: Hydro-Photon, Inc.
Manufacturer's URL:
Year of Manufacture: 2010
MSRP: Not Listed
Listed Weight (including batteries): 103 g (3.6 oz)
Measured Weight (including batteries): 102 g (3.6 oz)
Measured Weight (carrying case): 25 g (0.88 oz)
Listed Size: 15.5 cm (6.1 in) x 3.3 cm (1.5 in) x 2.2 cm (1.0 in)
Measured Size: 15.5 cm (6.1 in) x 3.8 cm (1.5 in) x 2.4 cm (0.9 in))
Battery Type: 2 x CR123 3V

Other information provided by Hydro-Photon:
UV Lamp Life: 8000 treatments
Battery Life: 100 0.5 L (16 oz) treatments with disposable batteries
40-50 treatments with rechargeable batteries

Packaging & SteriPEN

Product Description & Initial Impressions

I received the SteriPEN AdventurerOpti along with a carrying case, two disposable CR123 batteries, and the User’s Guide (in English, German, Spanish, and French).

The SteriPEN is a UV water purifier, which uses ultraviolet light to disrupt the DNA in bacteria, viruses, and protozoa. That means that they can’t reproduce and make me sick! The SteriPEN has received the Water Quality Association Gold Seal, and the User’s Guide tells me that “SteriPEN exceeds U.S. EPA Guide Standard for Testing Microbiological Water Purifiers, destroying over 99.9999% of bacteria, 99.99% of viruses, and 99.9% of protozoa when used as directed.”

The SteriPEN has two treatment settings: up to 0.5 L (16 fl oz) and 0.5-1 L (16-32 fl oz). The 0.5 L (16 fl oz) treatment is 48 seconds long, and the 1 L (32 fl oz) treatment is 90 seconds long. The unit is intended for use in clear water and at above-freezing temperatures (battery performance is affected by cold temperature). The AdventurerOpti has an optical water sensor next to the UV lamp to detect when the lamp is immersed in water and that it is safe to turn on the UV lamp.

The SteriPEN AdventurerOpti has a flashlight setting as well. It can be activated by pushing and holding the button for three seconds. The light stays on for three minutes, or can be turned off by pushing the button again.

The SteriPEN comes with a clear plastic cover for the lamp and optical water sensor. The cap can be removed with a firm pull. The handle of the SteriPEN is black and rubbery-feeling, with green highlights. Each side of the handle is branded with “SteriPEN AdventurerOpti”. The handle also has the button which controls the unit. Above the button is the text “Push once for 1L” and “Push twice for 0.5L”. Below the button is an indicator light which can be either red or green. The end of the handle is the battery compartment cover, which is held on by a coin screw. Inside the battery compartment is a “+” to indicate that the positive terminals of the batteries go towards the cover. There is a seal between the cover and the rest of the handle to prevent water entry into the battery compartment.

The carrying case is black neoprene on the front and back and mesh on the sides. It has a flap closure which is held in place with a hook-and-loop fastener. The back of the carrying case has a hook-and-loop strap for attaching to a belt or strap. The SteriPEN slips into the carrying case lamp-down, but doesn’t go all the way handle-down; the case is a bit tapered at the bottom end.

My initial thoughts on the unit are that it seems to be pretty sturdy, and the lamp cover is firmly enough attached that it won’t fall off, as well as robust enough to adequately protect the lamp.

I have to admit that water treatment is not something that I have historically been very diligent about, for several reasons. I find chemical treatments to be too slow for on the trail, and a leaking bottle of chlorine dioxide during a trip left me with a whole bunch of bleached clothes. I prefer filters to chemicals, but they’re still relatively slow unless I’m in camp at the end of the day, and they require maintenance kits, cleaning, and fiddling with little pieces. Most of the water I come across is quick-flowing and clear, so I usually just drink it with no treatment at all, with a nervous voice in the back of my head telling me I’m not being very smart. A summer of hiking in Europe (where absolutely everything qualifies as pasture) without treating water left me feeling very lucky that I didn’t get ill. I have no experience with UV purifiers, but the SteriPEN seems to be perfect for me; it has no moving parts, is quick to use, and won’t leak.

The manufacturer’s website is easy to navigate and well laid-out. The page for the AdventurerOpti gives information about UV water purification technology, the specifications for the unit, some pictures of the unit in operation, and a link to the User’s Guide. I had a very good idea of what I was receiving from looking at the website. I registered the SteriPEN that I received on the website. Although the website given in the User’s Guide for registration was incorrect, the correct page was easy to find on the website and the registration process was simple. The website gives information on the warranty (limited lifetime warranty for manufacturing defects) and how to submit a warranty claim. As well, there is a very useful Frequently Asked Questions (FAQ) section on the website.

Reading the Instructions

The User’s Guide for the SteriPEN AdventurerOpti is quite comprehensive in covering the operation of the unit as well as rather a lot of warnings about how to use it, and how not to use it.

The instructions for operation are straightforward. Push the button once or twice (depending on the volume of water), dip the UV lamp and optical water sensor into the water, and the lamp turns on. Agitate the water with the SteriPEN to ensure even treatment, and when the lamp turns off and the light turns green, the treatment is done. Easy. The guide also suggests drying the lamp with a clean cloth.

The guide to the indicator light signals is less straightforward. The meaning of the signal is dependent on whether the light is red or green, steady or flashing, what speed it’s flashing at, and if there’s any combination of red and green flashes. Basically, green means that the unit is ready to treat water or that treatment was completed successfully, red means that the treatment was unsuccessful or the battery is getting low, and a combination of green and red can mean some combination of those signals. For example, the signal for “1 L (32 fl oz) dose completed; battery getting low” is “green slow blinking with red flashes”. It’s a bit confusing and I’m sure I won’t remember all of the signals, but if I see red I’ll think about replacing the batteries or redoing a treatment.

Although the SteriPEN is intended for use in clear water and suggests filtering murky water prior to treatment (a pre-filter is available for this purpose), there are instructions for treating turbid water: double the treatment.

The 28 Warnings for Safe Use cover a wide range of topics. The ones that I made a particular note of are about not getting water in the battery compartment, not over-tightening the coin screw on the battery compartment, and the ones which remind the user that the SteriPEN doesn’t purify water clinging to the sides of a container or disinfect any surfaces such as the mouthpiece of a bottle. The instructions note that the flashlight should be used with the lamp cover in place to protect the lamp.

Trying it Out

Trying the SteriPEN The SteriPEN arrived with a piece of plastic preventing contact of the batteries to complete the circuit, so I removed the battery cover and the plastic. The coin screw was easy to turn with a coin or a hair clip (which I would be far more likely to have with me on a hike).

The manufacturer’s website indicates that the SteriPEN AdventurerOpti works best with containers with a minimum opening of 4.5 cm (1.75 in). The FAQ section on the website indicates that the SteriPEN is not intended for use in hydration bladders (though it can be used on water before or after being in a bladder). I filled out the “Contact Us” form on the website and asked the reason that the SteriPEN shouldn’t be used in hydration bladders, and received a response in less than 12 hours. There are three reasons: bladders are generally larger than 1 L (32 fl oz), and the SteriPEN is for use on up to 1 L (32 fl oz) at a time, any water in the tube will not be treated, and there is a risk of water getting caught in the creases of the bladder and not being treated. I generally carry a hydration bladder and/or a bottle with a 5 cm (2 in) opening, so I will be carrying a bottle more often during testing of this unit.

I filled my 650 mL (22 fl oz) bottle with water, pushed the button once for a 1 L (32 fl oz) treatment, and submerged the lamp and water sensor during the 15 second window for the unit to sense water (during which time the sensor flashed white and the indicator light flashed green). The UV lamp came on, and I agitated the water gently for the 90 second treatment. It felt like a long time, but I’m just impatient. When the treatment was complete, the lamp turned off and the green light flashed slowly, indicating that the treatment was successful.

The rubbery grip on the SteriPEN was easy to hold on to, and I didn’t feel like it was going to slip. However, having read the warnings about not submerging the unit and getting water in the battery compartment, I was a bit worried about dropping it in my bottle as I agitated the water. It would be nice if there were a short wrist lanyard attached to the SteriPEN to prevent me from dropping it in water, or a place that I could attach my own.

I dried the lamp using a spare microfiber cloth, which I will keep with the SteriPEN when I carry it on the trail.


The SteriPEN AdventurerOpti is an alternative to chemical or filter water treatments that has no moving parts, won’t leak, and acts quickly...perfect for me! I’m looking forward to testing the operation and convenience of the SteriPEN on the trail this summer.

Thumbs Up:
Quick water treatment
Clear instructions
Easy to operate

Thumbs Down:
No wrist lanyard to keep me from dropping it

Field Report – August 3, 2010

Field Conditions

Filling my Hydration Bladder I have carried the SteriPEN AdventurerOpti on 17 day-hikes in the two months since my Initial Report, and used it on three of them. As well, I’ve used it while camping on three nights. The details of the times that I used the SteriPEN follow:

May 21-23, 2010: 3-day climbing & camping trip, around 15 C (60 F) with some rain. I used the SteriPEN in camp to purify water that wasn’t going to be boiled. I treated four 1 L (32 fl oz) batches of clear water.

May 29, 2010: 10 km (6.2 mi) hike in the Purcells at around 15 C (60 F) with some rain. Used the SteriPEN in a 1.5 L (50 fl oz) hydration bladder with clear water from a creek, which was about 5 C (40 F). I purified between 0.5 L (16 fl oz) and 1 L (32 fl oz) of water.

June 5-6, 2010: I carried the SteriPEN on a 2-day search & rescue exercise, which included a pack inspection to see what we were all carrying. The evaluator was impressed that I actually had a water treatment method in my pack (most didn’t).

June 21-23, 2010: 3-day climbing, hiking, and camping trip in the Selkirks. Temperatures were 20-25 C (68-77 F) and I used the SteriPEN on three 1 L (32 fl oz) batches of clear creek water which was around 5 C (40 F).

June 26, 2010: I carried the SteriPEN on a 15 km (9.3 mi) dayhike up to an alpine lake. The temperature was about 25 C (77 F). My hydration bladder leaked all over the place while I was up there, so I suddenly had no water for the hike down. I used the SteriPEN to put another 1 L (32 fl oz) of clear lake water into my bladder.

July 17-18, 2010: I used the SteriPEN to purify creek water while camping on the side of a forestry service road. The temperature was about 20 C (68 F) and the water was about 7 C (45 F). I purified 2 L (68 fl oz) in three batches.

July 18, 2010: On a dayhike up to some alpine lakes I used the SteriPEN to treat 600 ml (20 fl oz) of water, which was at about 5 C (40 F). The ambient temperature was around 25 C (77 F).


I have had no trouble at all using the SteriPEN AdventurerOpti. It has worked perfectly every time I’ve tried to use it.
the SteriPEN in my bladder
I really enjoyed the quick purification time using the SteriPEN. It’s much faster and easier than any other method that I’ve used, and I didn’t hesitate to get the unit out of my pack and use it. That’s a great change for me, since I usually didn’t treat my water at all (depending on the location) previously. Previously, I didn’t carry anything for water purification for day-hiking, and now I never go without the SteriPEN. Although there isn’t the sense of having mechanically done something to the water (like with a filter), I felt like I was being a conscientious hiker. I haven’t gotten sick yet this year, so either it’s working or I’m still lucky!

All of the creeks and lakes that I’ve gotten water from have been clear. There have been a few floaties once in a while, but no turbidity. I haven’t needed to do any pre-filtering of the water.

Although I was given the reasons why the SteriPEN isn’t intended for use in hydration bladders, on two of the day-hikes that I used it on, I found myself suddenly with little water and not carrying a separate bottle. I kept the hose and mouthpiece out of the water source and stirred the water as much as I could during treatment. Better than nothing in a pinch, for sure.

I have found that in sunshine it can be difficult to see if the lamp illuminates once I put the wand into water. If I look through the side of my bottle it’s more obvious, but I can’t tell from the top. It has turned on every time, though.

Although the battery compartment seal is water-resistant, I have been cautious about getting too much water on it. Trying to keep enough of the handle out of the water to keep the seal dry and to keep a good grip on the unit means that I need to have my water bottle almost full to the brim to effectively use the SteriPEN, and has led to pulling the sensor just above the surface of the water several times. The lamp has immediately turned off, just as it’s supposed to. That’s a great safety feature. I re-started the full treatment in all cases.

I used the flashlight once while going down to the creek to get water in the dark. I had a headlamp on, but the extra light from the SteriPEN was nice. It was bright enough that I could certainly find my way to a water source with it, but I’m not sure what I’d do while I was actually treating water in that case...sit in the dark, I guess.

I have used the SteriPEN to treat 13 batches of water that were between 0.5 L and 1 L (16 to 32 fl oz). This is well below the 100 0.5 L (16 fl oz) treatments that is specified by the manufacturer for disposable batteries, so I’m not surprised that the original batteries are still going.

I have used a small microfiber cloth to wipe off the unit after each used, and stored the SteriPEN in its neoprene case. It still looks brand new.


I am really enjoying using the SteriPEN AdventurerOpti. I am carrying a water purification unit with me all the time, which means that I can get more water on day hikes as well as in camp overnight. The unit has performed flawlessly so far. I’m moving to a new area of British Columbia shortly, so I’ll have new terrain to get out and explore, and I’m looking forward to the SteriPEN going exploring with me. My outlook on water purification while hiking has shifted from “almost never” to “always”, which is much more intelligent.

Long Term Report – September 28, 2010

Field Conditions

collecting water
Treating water in a pot
Through August and September I have continued to carry the SteriPEN AdventurerOpti on all of my backcountry (and frontcountry) exploration. It has been carried on 18 days of hiking and search & rescue response or practice, and used during 4 of the days. As well, I have used it in camp (either backpacking or car camping) 3 nights. In the Long Term testing phase, I’ve treated 12 batches of water that were between 0.5 L and 1 L (16 to 32 fl oz) and 6 batches of water that were up to 0.5 L (16 fl oz). On all occasions, the water has been around 5 C (41 F).


I continue to enjoy using the SteriPEN. I find it very convenient and easy to use.

I have actually found that my whole approach to water in the backcountry has changed. I’ve actually found myself treating water and then thinking about whether I should drink it, at which point I usually kick myself for doubting whether the SteriPEN has been effective. I think that’s because it’s so easy and doesn’t require me to do anything mechanical or wait for chemicals or anything. Of course, considering that 6 months ago I would have drunk the water without treating it at all it’s a shocking shift. I take it as a good sign of my increased focus on water safety.

As in the Field Report period, all of my water sources have been clear, with no turbidity. I haven’t needed to prefilter the water.

I have continued to use my typical water bottle to collect and treat water. I have also tried using a small pot with 0.5 L (16 fl oz) of water. I found that the water in the pot was shallow enough that it was difficult to agitate the water and keep the sensor submerged. If I tilted the wand to submerge the sensor, part of the lamp was still out of the water, which basically bypassed the safety feature of the UV light only turning on if the lamp is in water. After trying the pot, I went back to using my bottle.

I’m still pretty cautious about getting the SteriPEN wet or dropping it into my bottle, but haven’t come up with any way to attach it to my wrist when I’m using it.

I have used the flashlight feature twice during the Long Term testing phase. I like the extra light for navigating to a water source, but still like to have my headlamp for when I’m using the SteriPEN to treat water.

I am still below the 100 0.5 L (16 fl oz) treatments advertised for disposable battery life, and I haven’t had to change the batteries yet. I have carried the SteriPEN in the neoprene case, and it looks brand new.


I love the SteriPEN. I have gone from a never-treat-the-water person to an always-treat-the-water person. It’s simple, easy to use, quick, and there aren’t any pieces to lose, clog, or break.

Thumbs Up:
Easy to use
Quick water treatment

Thumbs Down:
No way to attach a wrist lanyard

Thanks to Hydro-Photon and for the opportunity to test the SteriPEN AdventurerOpti. This is an item that has changed how I think about water in the backcountry!

Addendum - August 27, 2017

Late last summer, in 2016, the sixth year of water treatment with my AdventurerOpti, I had an issue. My pre-trip test showed that I needed to change the batteries, so I did that with no issue. Then, however, my purifier started doing strange things. When I pushed the button to initiate water treatment, the indicator light indicated “ready for treatment” and the optical water sensor flashed as expected. However, when I submerged the lamp and sensor in water, the lamp didn’t turn on. The sensor continued to flash for the treatment duration, and then the indicator light indicated a successful treatment. The same thing happened even if I didn’t put the purifier into water. In short, I couldn’t get the lamp to turn on, but the lights said everything was good. I checked the user guide and it said “If LED indicators show normal signals, but the lamp does not illuminate, do not consume. Contact SteriPEN support.”

I contacted SteriPEN through the form on their website. They replied to me the next day with a Return Authorization and instructions. Since it was already late in the year, I promptly forgot about it until the spring of 2017 when I realized I still didn’t have a working means of water treatment. Despite ten months having passed, I packed up my old SteriPEN and sent it off as instructed. I had no real expectations; I figured I’d either get nothing and need to purchase a new one or the manufacturer would help me out and give me a discount on a new one. After all, it had now been seven years since I got the original unit. I was surprised six weeks later to get home from work and find a brand new SteriPEN Adventurer Opti on my doorstep. What great customer service!!

I was previously impressed with the function of my UV water purifier. Now I am also impressed with the level of service provided by SteriPEN. I look forward to many more years of successful water treatment with my Adventurer Opti.

Read more gear reviews by Andrea Murland

Reviews > Water Treatment > Ultraviolet > SteriPEN Adventurer Opti > Test Report by Andrea Murland

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