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Reviews > Water Treatment > Ultraviolet > SteriPEN Adventurer Opti > Owner Review by jerry adams


April 25, 2012


NAME: Jerry Adams
EMAIL: jerryaadamsatyahoodotcom
AGE: 58
LOCATION: Portland, Oregon, USA
HEIGHT: 6' 1" (1.85 m)
WEIGHT: 195 lb (88.50 kg)

I started hiking about 45 years ago. My first backpack was 40 years ago. I currently try to do one backpack trip of 1 to 5 nights every month (which can be tricky in the winter). Mostly I stay in the Western half of Oregon and Washington. In recent years I have shifted to lightweight - my pack weight without food and water is about 12 lb (6 kg). I make a lot of my own gear - silnylon tarp-tent, bivy, synthetic bag, simple bag style pack.


Manufacturer: Hydro-Photon, Inc.
Year of Manufacture: 2011
Manufacturer's Website:
MSRP: US$89.95
Listed Weight: 3.6 oz (103 g)
Measured Weight: 3.6 oz (102 g)
Dimensions: 6.1x1.6x0.8 inches (15.7x3.9x2.4 cm)
Uses 2 CR123 batteries (Lithium)
Spare batteries weigh 1.2 oz (33 g)

The SteriPEN Adventurer Opti is a UV water purifier.

It treats all types of parasites - bacteria, Giardia, Crypto, and viruses.

The way it works is, push the button on the side, stick it in the container of water, swirl it around so that it stirs up all the water so it gets equally treated, and after a pre-set time it turns off. UV light is emitted from a lamp which kills the parasites. Maybe some parasites are just made sterile so they don't reproduce which prevents them from causing disease.

Either 1/2 liter (1 pint) or 1 liter (1 quart) can be treated at one time. Push the button once to treat 1 liter and the little green LED comes on steady. Push the button a second time to treat 1/2 liter and the little green LED blinks.

The business end has a 2 inch (5 cm) long UV lamp and a white LED. When it is put into water, the UV lamp comes on and the LED starts blinking. The LED is to detect if the UV lamp is pulled out of the water, in which case it turns off and a red LED comes on to show it failed. If the UV lamp is allowed to stay on when it's pulled out of the water, the UV light can injure humans. When the UV lamp is under water, the dangerous UV light is reflected off the water/air interface so it stays inside the water and is safe for humans.

A set of regular disposable batteries is supposed to treat 100 1/2 liters (pints). A set of rechargeable batteries is supposed to treat 40 to 50 1/2 liters (pints). I didn't get anywhere near this - see "Field Use" below. The UV lamp is supposed to last for 8000 treatments. I think it doesn't matter whether it's 1/2 or 1 liter treatments, the lifetime is determined by how many times it's turned on and off, not how long it runs. The lamp has to be replaced by the manufacturer, not the user.

The Opti requires a container with an opening at least 1.75 inches (4.25 cm). This is bigger than most water bottles. "Nalgene" type bottles will work. Any plastic or metal container can be used. A quartz container can't be used because it allows UV light to pass through it, but quartz containers are very unusual (except in a laboratory). The water depth has to be at least 2.5 inches (6.25 cm) so the container depth has to be at least 3 inches (7.5 cm) to allow a little headroom.

It takes 48 seconds to treat 1/2 liter and 90 seconds to treat 1 liter. After successful treatment, the green LED on the side blinks slowly. If it's successful but the batteries are getting near the end of life, it will blink green, with red flashes.

When the batteries were at end of life, it worked for part of the 48 or 90 second treatment, then turned off, and the red LED came on.

The Opti will only work on water that is fairly clear. If it is somewhat silty, they say to do 2 treatments. The silt in the water absorbs the UV light so it doesn't effectively kill parasites.

The Opti can't be used if it's below 32 F (0 C) but, in this case, warm the Opti inside a pocket for a while. In cold temperatures the batteries don't last as long. The Opti can't be used in water warmer than 140 F (60 C) which is hot to the touch. The Opti can't be used in water with ice cubes because the UV light won't penetrate the ice cubes so if there are parasites inside the ice cubes they won't be killed.

The Opti is black plastic with green trim and a clear cover over the UV lamp.

The Opti can also be used as a flashlight. Hold down the button for 3 seconds, and then the LED lamp will come on for 3 minutes and then turn off. This doesn't make it a very convenient flashlight, but would be good in an emergency.

The Opti does not change the taste or color like some other treatments. There is no pumping required like some other treatments.

Treating water in my cutoff soda bottle:


Button and LED on side of unit. The LED can be either red or green:

Side with button and LED

Business end - UV tube at lower right, LED at upper left:

Business end

Batteries removed. A coin can be used to unscrew the cap:

Batteries removed


I have used the Adventurer Opti for about 9 months. I have treated about 40 pints (1/2 liters).

First, I used some rechargeable CR123 batteries. I took a spare set of batteries with me. On the second 1/2 liter treated, the batteries failed - the red LED came on. I put in the spare batteries and then it worked for several treatments before they also failed.

Lesson learned is - don't use the rechargeable batteries that I got. Maybe, a different brand would work better, but from what I found on the internet, I'm skeptical. After that, I just used brand name disposable batteries.

Then I used Energizer disposable batteries. These worked fairly well. Over 8 months I successfully treated 28 1/2 liters before it quit working - on the 29th treatment it worked for about 1 second then turned off and the red LED came on. This is less than the advertised 100 treatments, but still usable.

Then I used two more of the same batch of Energizer disposable batteries. They treated 8 1/2 liters successfully. On the 9th treatment they failed.

The CR123 batteries were 3.25 volts when new. After a few treatments they were 3.08 volts. They gradually lost voltage until they were 3.01 volts and then they failed. I always measured them after the trip was over, after the batteries rested. I suspect that immediately after use, the voltage is lower, then gradually increases a little. I wanted to be able to measure voltage to determine how many treatments were left on the batteries so I could avoid taking spare batteries if not needed. Like, if the voltage is 3.02 volts then it has at least 8 1/2 liter treatment capacity. If the voltage is 3.03 volts then 16 treatments. But, I've decided the voltage difference is so small it would be difficult to know how many treatments are left, and the Opti is kind of finicky so I just carry spare batteries which only weigh an extra 1.15 ounces (33 g) which is fairly lightweight.

The first time I used the Opti I used my 0.9 liter Titanium Evernew pot. The problem is, if I put in 1/2 liter, then it's not deep enough for the Opti to work, and I can't put in more than about 0.9 liters (0.95 quarts) which is a little wasteful if I put the Opti on the 1 liter treatment cycle. I suppose I could manually time 81 seconds or just don't worry about the wasted time.

What I started doing is, to take a 2 liter soda bottle, measure 1 liter and put a mark, and then cut the bottle off about 1 inch (2 cm) higher to allow some head room. I also have marks at 1 cup and 1 pint (1/4 and 1/2 liter) which I use for measuring water for cooking. This weighs 0.6 ounces (16 g). I watch my weight pretty closely, but this fits into my weight budget pretty good.

What I like about the soda bottle treatment container is, it's easy to swirl the water around good so the Opti is maximally effective.

I don't treat water that I'm going to heat, which is most of the water I drink. I treat only 2 or 3 1/2 liters per day. I treat 1/2 liter and put into my water bottle which holds just that much. I use a 4 liter (1 gallon) Platypus water container to hold untreated water. I use the treatment container to scoop water out of the stream or lake into the Platypus.

The Opti doesn't work so good in silty water because the silt absorbs some of the UV light. If I put the water in the Platypus and let it settle for a few hours or overnight, much of the silt settles to the bottom and alleviates this problem.

When I'm cooking a meal, I use the treatment container to measure out the required amount for each course. Since I use the treatment container for three things (scooping water, measuring for cooking, and treatment) I feel okay about carrying an extra item.

One problem with the Opti, is the button is hard to push. I have found that if I push it very firmly I can get it to work. If I push directly in the middle it works better. If I had arthritis or something this might make the Opti unusable.

Using the Opti is easier than pumping a filter, but is more difficult than just plopping some pills in the water. I have to carefully hold the Opti so it's completely in the water and stir for 48 seconds. If it's on the ground and I'm bending over my back gets a little stiff. Occasionally the Opti will accidentally come out of the water and turn off, so I have to start over. Once I got the hang of it though, this inconvenience was minor and easier than pumping a filter


I have mixed feelings about the Opti - I like the low weight, no chemicals, and ease of use but the reliability is marginal.

If I get brand name batteries and always carry a spare set, and after I have used it a few times to develop a system that works for me, then I have found the Opti to be fairly reliable. I have got the hang of how to push the button so that isn't a problem anymore. Using the Opti is easier than pumping a filter but more difficult than plopping in some chemicals. With the spare batteries it weighs less than 5 ounces (140 g) which is less than almost any filter. Chemical treatments weigh less, but I don't like the taste and I am concerned that the chemicals aren't totally safe.

In the event the Opti doesn't work, I'll just drink untreated water. Most of the time, water in the wilderness is safe or would only cause a minor illness. I figure that the reason to treat water is, that eventually I'll get sick if I always drink untreated water, but the chance of this the one time the Opti might fail is unlikely.

If I could find a filter that weighed as little as the Opti, I might switch to that.


Light weight

Works on all organisms

No bad tastes or possibly unsafe chemicals

Water is immediately available

No pumping


It's complicated and there are potential problems I had to sort through. Being a nerdly engineer, figuring out complicated things might be considered a pro?

The Opti is less reliable than other treatments, but I'm not too worried because I'm not sure water treatment is really required and the chance of major illness is low for the one time the Opti might fail

This report was created with the Report Writer Version 1.5 Copyright 2012. All rights reserved.
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Reviews > Water Treatment > Ultraviolet > SteriPEN Adventurer Opti > Owner Review by jerry adams

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