SteriPEN adventurer Opti

Image courtesy of SteriPEN

By Dave Wilkes

Imagine if you will, me standing next to a mountain stream on the scenic slopes of Mt Adams with a water filter that has been my long time and faithful companion, for many backpacking and hiking trips over the years. The pump has supplied me with some of the finest tasting and refreshing water I have ever consumed. However one tiny tidbit of information keeps going around in my head, making the filter little more use than a large rock. Is the pump broken you may ask? No. Did I forget or lose a necessary part? No, again. So what one unsubstantiated piece of information could make an otherwise perfectly functioning water filter useless? Well, I’ll tell you. While picking up my climbing permit, the forest ranger mentioned that the flowing water on the west side of the mountain was contaminated due to climbers not using the human waste pack out kits as they are supposed to.

My filter is designed to filter out sediment and parasites, and to my knowledge (since I have never become ill) has done a fine job. However, it is not effective against viruses and/or bacteria. So that delightful mountain stream, so cold and probably quite refreshing, could be a delivery system for some very nasty surprises to any who drink it untreated.

Image courtesy of SteriPEN

Fast forward about 6 months and I have in my hand a compact little device, weighing in at a mere 3.6 oz (102 g), less than 1/3^rd the weight and size of my pump. A device that not only will kill parasites, but render bacteria and viruses harmless as well.

The wonder device I am referring to is the SteriPEN adventurer Opti. This is the latest incarnation of the SteriPEN devices and is the smallest and lightest of them. The device uses ultraviolet light to sterilize 1 L of water in as little as 90 seconds. It has a small LED that serves double duty for sensing when the UV lamp is immersed in water and can be used as a flashlight. The manufacturer specifications are as follows:

• Weight: 103g/3.6 oz. with batteries. [I verified the weight with my own scale and this is accurate]
• Size: 15.5cm. (6.1in.) x 3.3cm. (1.5in.) x 2.2cm. (1.0in.)
• Battery: Uses two CR123 batteries (included)
• Battery life: Disposable — 100 treatments (16oz./0.5L); Rechargeable — 40-50 treatments (16oz./0.5L)
• UV Lamp Life: 8,000 treatments

Now for total disclosure, about 2 years ago I was on a group climb where the leader of the group had two older models of the SteriPEN. In using them side by side with my water filter, I found it to be quicker and require far less effort to use. About the only drawback was that some of the folks complained about the sediment that was left in the bottom of their water bottles (something easily remedied had they simply pre-filter the water through a cloth bandanna). I have resisted purchasing a SteriPEN as my pumps have served me so well over the years and I am more confidant that I could fix a malfunctioning pump than a broken UV bulb or dead batteries in the backcountry. But as I have been asked to review this (actually I asked to review it) and I have heard that the latest versions of the SteriPEN are far more reliable than the originals I decided to give it a try.

Image courtesy of SteriPEN

After receiving the device I gave it a full inspection and verified it works by turning it on and immersing it in some tap water. The design of the device seems to put a high value on the product only operating when immersed in water and there is mention on the web site that this is to prevent direct exposure to the UV light that could cause skin and/or eye damage. I tried to see if I could ‘fake’ out the sensor by covering it with my hand and operating it when wet but not immersed, but was unable to cause it to operate when not immersed. It looks like this safety precaution is quite effective.

In examining the device I have found one weakness in the design. The battery cover is made out of very thin metal and small spring pushes against only one end. The result is a small gap where the cap does not fully seat on the gasket. I was originally going to send it back thinking this was a flaw, but then noticed this same issue with the unit used in one of the photos on the SteriPEN web site. I will be keeping a close eye on this as well as inspecting the batteries often looking for any sign of corrosion.

I invite you to follow along with me over the next 3 months as I use this little device, see how it performs and if it can withstand the rigors involved in biking, hiking, backpacking, and climbing. I also invite you to participate in discussing this product as well as many more topics in the 4AllOutdoors Forms.

UPDATE May 30 2010

Is this Willy Wonka's chocolate river?

So far rain has kept most of the available water in my area quite muddy, which is quite odd since over the years I have had very little  trouble finding clear water…sometimes I think Mother Nature just has something against me (test rain gear…no rain, test snow shoes…poorest snow in years, test SteriPen…nothing but muddy water). Maybe I should consider testing things like first aid kits and bug repellent?
The first time I used the SteriPen while hiking the water was quite brown from mud. As such I did not really trust it to sanitize the water but tasted it anyway. Between the color and the muddy taste, I did not drink more than a sip. Being a day hike, I did not have the luxury to allow the water to sit and settle, and I did not have a bandana handy to filter it, so I ended up poring it out at the end of the hike. I carried the SteriPen along on a few more day hikes where I did not get the opportunity to use it (water too muddy, trip too short to need additional water, etc). This Sunday I took the kids for a hike in a local canyon prepared to pre-filter the muddy water (brought some water for them but an empty bottle for me)…but my luck held out, and despite all the rain we have been getting the water was flowing clear?!?! I collected and sanitized 1L of water in a white Nalgene bottle. I found it difficult to see if the lamp was operating until I angled it such that it was very close to the side of the bottle. Then I removed it from the water before checking if it was done…oops! I recalled from the instructions that if the cycle is interrupted, the small indicator light will be red. I looked at this and it was off, so I assumed the cycle had completed. In thinking about this, I could not help but think that some sort of ‘beep’ indicating the start and end of the cycle could be useful. Of course I could have simply ran it through a second cycle if I wanted to be sure. Despite a few floating particles, the water was clear and tasted wonderful! Since the light cannot penetrate solid materials, I worry about what little ‘nasties’ could be in the particles floating in the water. As such I think in the future I will plan to use some sort of pre-filter, even for clear looking water.
I found operating the SteriPen on a muddy stream bank to be a bit of a juggling act. I feared losing (or stepping on) the clear protective cover, so I kept it in my hand. I also had my trekking pole, my water bottle, and the SteriPen…oh, yea my camera…I realized I was quickly running out of hands. I could not help but think that some sort of lanyard attaching the cover to the body of the SteriPen would have been helpful.
So far I like that this product is far lighter than my filters, and it is quite easy to use. I don’t normally like to trust my safety to battery operated gear, but this seems to be fairly durable and function well (and I always carry water purification tablets as a backup anyway). I will need to pick up a backup battery just in case. I like that it is effective against parasites as well as bacteria and viruses. I worry about it not functioning in dirty water or against anything that may be hiding in the small particles that can be in even clean looking water, so I think some sort of pre-filter is a must.
I look forward to using this product more as the weather warms up. Since most places I travel have ample supplies of water, this should allow me to carry less and fill up more often due to it being simpler and quicker to operate than my filters.

Update Aug 3 2010

I have to start by saying that it does perform exactly as advertised. It has worked fine, and along those lines, I have no complaints. There are a few details about the design and use that I find limit usability for me, but there are also some features that I really like.

Above I mention that most of the places I go have plenty of clear water available. As luck would have it, the conditions I experienced during this review were not “normal” for me. Most of the water sources I encountered were quite muddy and some were simply too small to easily fill a water bottle without some sort of pump. As such I used a bandanna as a pre-filter, and in one case I used my pump filter to fill the water bottle and then the SteriPen (I will get into more detail about that below). Pre-filtering the water was effective as long as the water source was deep enough or I had a second bottle available (scoop with one bottle, cover with the bandanna and pour into second bottle). I had no way to know that the SteriPen was effective at killing all the little nasties, but I did note that it did nothing for the muddy taste (to be fair it is not intended to improve taste). While on Mt Adams, the only source of running water was a small trickle of melt water running through some rocks. I was able to dig a pool big enough to use my filter to pump water into our bottles. This made filling the bottles easer, and we did not have to wait until the mud stirred up by the digging settled. Since we were downhill from other camps I was concerned about what could be in the water that my filter could not take care of (bacteria and virus from human waste), so I was glad to have the SteriPen and used it on at least 9L of water in a single morning. If we did not have the SteriPen we would have had to melt snow for all of our water needs. On a side note, I noticed that the water, even after filtration, had a muddy taste, so obviously even the filter can’t guarantee good tasting water.

In bright daylight I found it difficult to see the light from the indicator light as well as the dim glow of the UV lamp, so knowing it was operating was difficult, same with knowing when it was finished. On the Mt Adams trip, one of the folks also had a SteriPen (Journey LCD) along with the bottle adapter. He preferred being able to insert the SteriPen into the bottle and inverting it to having to hold mine in place and stir.

If I were to suggest any improvements to the product it would be: 1) Some sort of audible indication to the start/finish of operation. 2) Maybe move the button/indicator light to the bottom of the device so it is more visible when in use (when it is in the bottle, the bottom is facing the user, not the side). 3) A bottle adapter similar to what is available for the other styles of SteriPen.

So, you may be asking what my future plans are for the SteriPen? Well there are some conditions where my old filter works better for me, but for many (most?) of my normal hiking/backpacking the SteriPen should be as good if not better than my filter. Being lighter and simpler to operate, I will bring it on short trips where I would otherwise have just carried more water. On alpine trips such as Mt Adams, especially late in the season, I may also bring my pump, but I will definitely bring the SteriPen (too many people refuse to use their “targets”). In the spring when the water is muddy I might simply use my pump and save on the weight of the SteriPen.

I would like to thank the folks at 4AllOutdoors.org and the makers of SteriPEN for the opportunity to review this fine product. It was a fun product to test and I anticipate using it for the foreseeable future.

Be Sociable, Share!

•