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SteriPEN Adventurer Water Purifier REVIEW

A reasonably light and very effective means of purifying water to EPA purifier standards.


Overall Rating: Recommended

The SteriPEN Adventurer gets a Recommended rating on several grounds. It is quite light, it works faster than the competing technologies of filters and chemicals, it handles viruses which filters generally don't stop, and there are no chemical residues to worry about. In addition, most chemical treatments have problems with protozoa such as Giardia lamblia and have to be left for a very long time to be fully reliable, up to hours on end for some chemicals.

It doesn't get a Highly Recommended rating because it is still a little heavier than could be and it is a bit hungry on batteries. Should a similar unit come out which uses UV LEDs instead of the gas discharge lamp, I suspect it might achieve our highest rating, but the technology may take several years yet to arrive.

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by Roger Caffin |

SteriPEN Adventurer Water Purifier REVIEW


There is nothing worse than getting sick while out walking, and one cause is contaminated water. A big problem is you very often do not know whether the water in front of you is safe or not. There may be 'bugs' in the water: very small viruses, middle-sized bacteria or largish protozoa. There are four common ways used to convert water of doubtful quality into something you can safely drink - or to make those bugs harmless.

  • Boiling - takes a lot of time and fuel, leaves water hot or tasting 'flat'
  • Filtering - does not take out the very small viruses
  • Chemicals - do not always work reliably, may take hours to be effective 1
  • UV light - as reviewed here

Boiling, though it consumes fuel and time, is very effective if you do it as part of cooking. Filters can be heavy, have limited filter life and with one exception filters do not remove viruses. Since those little rotaviruses (for example) are responsible for a lot of dysentery, it is unfortunate that filters let them through. There are a lot of different chemicals on the market for treating water, including iodine, chlorine and chlorine dioxide, but they all have the serious problems of residual smell and taste. In addition some by-products of these chemicals are not very nice.

The chemicals do work quite well against most viruses and bacteria and are very widely used for this purpose. However, their efficacy against protozoans (such as Giardia lamblia and Cryptospordium spp.) in cyst form2 is questionable within the short contact times suggested by most manufacturers (< 30 minutes). This is because protozoa have a very hard shell around them a lot of the time. This concern has been validated in the United States during the failure of various chlorine-disinfection facilities in water distribution systems, with protozooan outbreaks as a result of short contact times. The risk of outbreaks in Europe has decreased dramatically in recent years, and this may result from increased efficacy of chlorine dioxide against protozooans in cyst form. Unfortunately, little research has been performed to understand why chlorine dioxide may be more efficacious against cysts. Early findings suggest that, unlike chlorine or iodine, chlorine dioxide's molecular structure is able to permeate the cyst wall without becoming inactivated.

Lacking a quick, perfectly effective chemical treatment, we are left with UV light, which has been used to deal with 'bugs' and purify water as far back as 1910. It has been used commercially for applications such as bottling plants and extensively for chemical-free community water supplies, and its popularity is increasing. However, you should note that UV treatment has no effect on any chemicals which might be in the water - especially nasties like agro-chemicals, solvents and so on. You will need to watch where you get your water from - but you're probably doing that already.

What’s Good

  • Effortless operation
  • Lighter than any filter
  • Works for all bugs to EPA standards
  • Treats 1 litre (1 quart) in 90 seconds
  • No chemical smells or residuals
  • Can use rechargeable batteries

What’s Not So Good

  • It isn't cheap
  • It relies on batteries, which it loads very heavily
  • Batteries are a little expensive (but cheaper than most filter cartridges)
  • I worry about breaking the quartz lamp cover
  • Solar Charger is a bit heavy - an overkill design



Hydro-Photon Inc


2006 SteriPEN Adventurer


  • Basic Unit with Lamp cover and batteries 101 g (3.56 oz)
  • Nylon Sheath 28 g (1 oz)
  • Two spare CR123 Lithium cells 31 g (1.1 oz)
  • Solar Charger 160 g (5.64 oz)
  • Foam cover 26 g (0.92 oz)


  • SteriPEN Adventurer 160 x 40 x 23 mm (6.2 x 1.5 x 0.9 in)
  • Solar Charger 180 x 90 x 35 mm (7 x 3.5 x 1.3 in)

  SteriPEN Adventurer Case

Plastic, non-slippery

  Lamp housing


  UV wavelength

254 nm, in the deep UV-C range

  UV transmission

Negligible through common plastics and glass

  System Control

Embedded microprocessor with safety interlocks

  Estimated battery life

About 60 L (60 qt) for 2 non-rechargeable cells in warm weather

  Solar Cell Area

130 x 55 mm (5 x 2.2 in)


US$129.95 for SteriPEN Adventurer; US$49.95 for the solar charger


A serious caution should be given here as this whole area of water treatment or purification is a minefield. Each vendor of a purification product will present a threatening analysis of the water problem and a glowing analysis of the effectiveness of the product he or she is selling. Unfortunately, while the sales pitches may be fairly truthful they are not always complete. I have found that the bits which get glossed over or left out are sometimes rather critical. Well, I guess no manufacturer wants to tell you the bad bits. Also, there is a specialised jargon involved, as discussed below. It can all be very confusing.

However, I am also aware that some products on the market are relatively ineffectual, and others use a lot of 'weasel words' in their claims. The manager of AccuFilter went too far and ended up in jail in 1996 for fraud after being prosecuted by the EPA for the second time. On the other hand, the information provided with the SteriPEN Adventurer seems complete and credible.

In real life many walkers never bother treating their water: they are just careful where they get it from - and they survive. If you combine this caution with the UV treatment, you should be doing well.

Method of SteriPEN Operation

Each photon of UV light contains some energy, and if the wavelength of the UV light is short enough the energy can be sufficient to cause a change somewhere in the chemical bonds inside the bugs. For instance, if the bug has DNA, the UV light can cause the thymine bases in the DNA to lock up with each other, which prevents the bugs from replicating (breeding). In general, if the bugs can't breed and multiply inside you, they can't do you any harm. Of course, you need fairly energetic photons for this, but light in the UV-C band can do this. A common source of this is a discharge lamp emitting at 254 nanometres (nm), although some fluorescent lamps can also be used. The EPA has a lengthy document 3 on the whole subject, although it is primarily focused on industrial-sized systems.

Large discharge lamps with adequate power came first; very small ones with enough power were developed only more recently. The SteriPEN uses one such small UV-C lamp, which looks very similar to the Philips TUV4T5 Germicidal Sterilamp used in the Aquastar product. The SteriPEN Adventurer uses a microprocessor to control the operation and is powered by two CR123 (photo) lithium batteries. The company claims the lamp will provide at least 9,000 effective doses of UV but to be on the safe side they have limited the operation to 5,000 doses, and the unit gives a warning when you have passed 4,900 doses. They can replace the lamp. I would add that 5,000 doses is a lot of water treated.

Effectiveness of UV-C light and the SteriPEN Adventurer

It's no use taking something which is not going to work. Those home-made gravity-powered filters using a plug of cotton wool may be very light and very cheap, but they are not going to stop any viruses, nor any bacteria, and probably won't stop protozoa. They might make the water look clean and give you a happy feeling, but that feeling might change to unhappiness a day later if you get dysentery. There are EPA standards for water purification which are designed to protect your health, and it is wise to use a purification method which meets those standards. In passing, you should note that while many filters meet the EPA standards for protozoa and bacteria they do not normally meet the standard for viruses. Only a product which meets the EPA standards for all three sorts of bugs can qualify as a 'purifier': the use of the word is legally restricted in this context.

It has long been known that UV light can disable viruses and bacteria. Up until recently it was thought that UV light could not kill protozoa, but in the 90s it was found that researchers were asking the wrong question. UV light does not 'kill' the protozoa, but it does stop them from reproducing inside your gut, and as explained above if they can't breed they can't hurt you. Once this was understood the popularity of UV-C treatment for community water treatment started to rise. However, some non-UV water-purification companies still do not even acknowledge UV treatment as an option.

While this may be getting a shade esoteric, field tests have shown that our waterways are starting to show traces of certain hormones, antibiotics, fragments of recombinant DNA and RNA and other complex biological agents. They are coming from industrial processes, agricultural wastes and sewage treatment plants. I have seen data that suggests the same UV radiation will incapacitate some of these nasties as well.

The big question then is whether the SteriPEN Adventurer meets EPA standards and whether it has EPA registration. I asked the company about this, and they replied:

While our company is registered with the US EPA (company number - 73679), the EPA does not certify non-chemical water purifiers. As SteriPEN uses no chemicals it is not certified by the EPA. Non chemical systems such as ours and filters may be tested to the EPA standard. If these non-chemical systems meet the requirements of the EPA protocol then their literature generally states "meets US EPA protocol."

According to the Lab Test Reports I have read the SteriPEN Adventurer (and the older Classic) do meet the EPA requirements for treating all three sorts of bugs, and the SteriPEN Adventurer is advertised as a 'water purification device.' Backpacking Light has no means of running the very complex biological tests required for this so we will rely on the work of the independent test labs. I am satisfied by these reports.


Steripen - 1 The SteriPEN Adventurer.

The pre-production prototype unit we received is shown here. The main difference between it and the production version seems to be the direction of the printing by the button. The black and yellow body holds two CR123 lithium (photo) batteries and the electronics needed to drive the UV lamp and control the operation. The little red arrow at the bottom of the picture points to a small pushbutton, which is the only control on the whole unit. The little green arrow to the right points to a LED which shines either red or green. The blue arrow points to a metal electrode: there is one of these on each side of the unit and they sense the presence of water. Somewhere inside the unit there is a lamp temperature sensor. The long glass tube is a strong quartz envelope enclosing the UV lamp itself. When traveling it is wise to put the cover over the lamp: it clips on very firmly.

To operate the unit you remove the cover from over the lamp, press the button once (for 1 litre) or twice (for 0.5 litre), and put the unit in the water to be treated. The metal electrodes must be below the surface of the water. The lamp comes on and stays on for the required time, then turns off. You are advised to stir the lamp around in the water a bit to make sure you irradiate all the water. The length of exposure depends on the number of button presses and the temperature of the unit; the microprocessor will calculate this for you. The variation in dosage time due to temperature is not large. There is some variation in efficiency of UV generation with temperature. The UV action on the bugs is not significantly affected by the water temperature.

The manual or booklet which came with the pre-production version had very brief operating instructions on page 3, while the rest of the booklet was devoted to marketing waffle. This is a pity - a smaller booklet with better instructions would have been appreciated. It may be that the production version will be better. Ultra-lightweight walkers may take some exception to the ridiculous claim on page 2 that 'With the SteriPEN Adventurer, you're carrying hundreds of gallons of pure water in your backpack ...' However, maybe I am being too harsh.

Safety Matters

Steripen - 2 Blue Light coming from the lamp - or not, depending on the angle of view.

If exposure to the UV light can bump off the bugs, what will it do to you? This is the obvious question. This was addressed in a document entitled 'Common Questions' which I received, but I am not sure whether this document normally ships with the SteriPEN unit. As the document explains, UV light will not go through either glass or the common plastics; these materials block the UV. In addition, the company says the UV light bounces off the water/air interface at the top of the bottle.

In the pictures to the left the discharge can be seen in picture A, but it seems to be missing in picture B. In the case of picture B the lamp is still on, but the viewing angle from above is such that the blue light is being reflected off the water/air interface. In picture A you can see the blue light, but this is visible blue light, not the UV-C light. The UV has been blocked by the glass wall of the bottle. You can see visible blue light from the top of the water. The company claims that the UV light will not escape in this way but will rather be reflected off the water/air interface. They claim to have checked this with a UV light meter.

Another obvious concern is the effect on your eyes if you could turn the unit on before putting it in the water and got the UV in your eyes. Well, you can press the button, but the microprocessor has a mind of its own and for reasons of safety won't turn the lamp on until it senses water at the metal electrodes. For this to happen the lamp has to be underwater. So far so good. If you take the lamp out of the water while the UV lamp is running the microprocessor will detect the loss of water and shut the lamp off in about one second. It will also turn the LED on with a red colour as a warning that the treatment time was not completed. However, it takes about a second or two for the loss of water to be sensed, and in this time the UV light may be shining in your eyes, so don't pull the unit out of the water while it is turned on!

So why can't you put the unit in the water first, before pressing the button? The reason is again safety. It would be safe enough if the lamp really was under water, but this may not be so. If the bottom of the unit is wet from the last immersion, the water sensor can be fooled into thinking that the unit is under water even when it is out of the water. The unit could be fooled into thinking it was safely under water and thus turn on in your hand as soon as you press the button - and blast your eyes. To prevent this the microprocessor has a rule that the water sensor must be 'dry' when you press the button for it to work. There is a trap here: if the bottom of the unit is still wet from the last immersion when you press the button, the unit may refuse to operate. You may have to brush the sensors dry with a bit of rag before you push the buttons. I was caught a couple of times like this.

Field Testing

This unit may have only one (input) button and one (output) LED, but it does have a microprocessor inside it, and using it sometimes seems almost as complex as programming a VCR. Well, not quite, but I found the following 'features' from testing and reading the User Guide.

  • You have to turn the unit on before you put the lamp in the water.
            That is, putting the lamp in the water first does not work!
  • Pressing the button once turns the green LED on, first steady, then flashing fairly quickly.
            The unit requires quite a definite press of the button to work: it is not hair trigger
  • Pressing the button a second time makes the green LED flash quickly anyhow.

  •         However, I can't tell beforehand whether it has been set to treat 1 litre or 0.5 litre.
  • The green LED goes off when the UV lamp goes on.
            But if it flashes slowly while the lamp is on it means you are between 4,900 and 5,000 cycles: a warning.
  • When the treatment is complete the LED will either flash slowly (for 1 L) or just stay on (for 0.5 L).
            More importantly the UV lamp goes off, which is much more noticeable.
  • If you take the unit out of the water before the time is up the UV lamp goes off within about 1 second and the LED glows red.
            but putting the lamp back in the water does not turn the UV lamp back on.
  • If you leave the unit turned on in the air, it will time out after about 15 seconds and turn off by itself.
            It is supposed to give one red flash when it times out.
  • Red flashing is obviously a warning, and has two meanings:
            fast flashing: low batteries - flashes for 8 seconds.
            slow flashing: lamp has done 5,000 operations and should be replaced.
  • You can cancel the operation when the LED has turned red by pressing the button for a moment.
  • You must dry the two sensors before you try to treat the second batch, or it may think the unit is in water still.
            This can be a real trap if you are not thinking!
  • Getting the lamp cover off is hard work: do it carefully so you do not break the lamp!
  • There is no residual disinfection property like with chlorine and iodine.
            More care may therefore be needed to keep the treated water clean.

Steripen - 3 Putting the SteriPEN in various water containers: it does not work with small-necked PET bottles.

Not listed above as a feature is the speed of operation, but that is because it is worth a separate comment. I have used most of the available filters over the years, and they take time to set up and then you have to sit there and pump for a while. That is, if you don't have to stop and clean the filter half-way through. The pumping can be hard work. With the SteriPEN Adventurer I just sit there and stir gently for 90 seconds. Well, to be honest, my wife often does it while I do other things. With chemicals it does not take long to drop a pill in the water, or to mix Part A with Part B, but then you have to wait for 15 - 30 minutes (or more) before the water is safe. When you are thirsty, this can be a long time ... I find I can wait the 90 seconds for the SteriPEN Adventurer fairly easily.

I did find that the SteriPEN Adventurer does not fit into every possible water container. In particular, it does not fit down the neck of my favourite ultra-light PET water bottles - which come free with every 1.25 litre bottle of fizzy mineral water. So using the SteriPEN has meant I have had to change how I treat our drinking water: now I do it in our cooking pot, with continuous stirring. I can pour the treated water into a bottle later. Mind you, since the lamp radiates out sideways rather than downwards the shape of the pot is just right for the light distribution from the lamp. I don't think trying to treat water in a tall thin bottle is a good idea anyhow as the bottom region would not get much light. Alan Dixon has used a wide-mouthed hydration bladder for treating his water, as shown in the middle picture here, but the height of the bladder could be a problem. I don't suggest you do it this way.

You should note that pouring water from one bottle into another after UV treatment is not without a risk: there is no residual purifying action once the lamp has been turned off. With Coghlans iodine tablets I know there is a trace of iodine still in the water which can handle later contamination. Since I currently use the same type of PET bottles for treated and untreated water, I have to be very careful to distinguish between the two (I put a spare rubber band around the neck of the treated water bottle)! Still, I can always use a little bit of the treated water to rinse out a 'contaminated' bottle; the chance of a harmful number of bugs being left in the bottle after doing that is very low.

Needless to say, my testing has been done on fairly clear water. After all, if the water is so turbid you can't see through it then the UV light won't get through it to the bugs either. It may make some sense to filter any mucky water through a bandanna or similar first - or to find better water if you can. But more importantly the presence of a small amount of dirt or organic matter in the water will not greatly affect the operation of UV light. This is very different from using a chemical, where organic matter in the water will soak up the chemical and may leave the bugs alive.

The User Guide recommends you do not use the SteriPEN when it is at a temperature below freezing. There are two good reasons for this. The first is that water below freezing may be ... ice. Bit hard to stir the SteriPEN Adventurer in a block of ice! The second is that battery life for the 3 volt CR123A lithium cells does fall badly below freezing as shown in the graph below, and you need to look after those batteries. You may be aware that the Eveready e2 1.5 volt AA and AAA lithium cells have much better life in the cold than this, but that is because they have a different chemistry. The SteriPEN Adventurer is quite small, so it is no hassle to stick it in your pocket for a while to warm up.

I have found that people are sometimes more willing to use UV disinfection than chemicals because they want to avoid both the smell and taste of the chemicals, and to avoid their by-products. This is not a quantitative assessment, but for many walkers it is a real issue. One thing I can say is that the SteriPEN Adventurer does not seem to alter the taste of the water at all. This method of UV treatment may be the wave of the future.


With the SteriPEN Adventurer you are dependent on the life of the two CR123A lithium batteries, and those little batteries are not cheap. A good pair of these will cost in the region of US$12 - US$14, although cheaper ones may be available (with less life). You can also use the unit with rechargeable lithium cells, and the company sells a padded carry case with a built-in solar panel on the lid for recharging. The company claims that the cost of operation amounts to about 11 cents per gallon (4 liters) purified with rechargeable batteries, but I have no idea how much they are paying for their batteries, and prices and quality can vary widely. Testing was done with both the rechargeable CR123A cells and the readily available standard CR123A non-rechargeable lithium cells.

Steripen - 4 Life of a CR123 under pulsed load (courtesy Duracell).

The current drain from the batteries starts out at about 1 Amp: this is a lot for the little CR123 cells. Fortunately they were designed for photographic use and can take that sort of load in short bursts. After about a minute, when the lamp has warmed up, the current drain drops to about 0.9 Amps. This represents a load of about 2.7 Watts (per cell), and typical battery life at that sort of continuous load is about 0.85 hours to 2.0 volts and 1.0 hours to 1.55 volts. I do not know the minimum voltage which the SteriPEN Adventurer will operate at as this is a little hard to test. However, this does not matter very much since when these cells reach their end of life the cell voltage falls quite fast.

With a pulsed load the life of the CR123A cell is longer, and we can treat the SteriPEN as a pulsed load, albeit a fairly harsh one. Using a graph from Duracell, we can see (thin blue cross hairs on the red line) that at 0.9 Amps and a low duty cycle the life of a cell can be as long as about 1,800 x 3 seconds to 2.0 volts, at 'room temperature' (RT). This is 90 minutes. The SteriPEN Adventurer takes about 90 seconds to treat 1 litre of water. This suggests that one set of CR123A Lithium cells will treat 60 litres of water, at 'room temperature.' At US$13 for two cells, that is about 22 cents per litre. I can't tell you how many days walking this translates to as everyone's water use is different. Remember that if you are going to boil some of your water for cooking, you do not need to treat that part with UV first.

The graph also illustrates the very bad effect sub-zero temperatures have on battery life! You can happily use the SteriPEN Adventurer in the snow if you warm it and especially the batteries up to body temperature first.

Steripen - 5 SteriPEN Adventurer battery compartment.

Replacing the batteries in the field is very simple with the SteriPEN Adventurer. The end cap is held in place by a screw, but this has a huge head with a huge slot (red arrow) which I can operate with my thumbnail or almost anything. It does not seem to jam at all. Undo the screw and the cap comes off. The batteries just slide out. Insert new ones with the small terminal pointed upwards as shown in the picture and replace the cap - there is a small retaining lug at the right hand side of the picture below the green arrow to hook in place. If you forget and put the batteries in upside down it does not matter as nothing will happen. There is a shaped contact at the tip of the green arrow which will only mate with the small battery terminal; it won't connect with the large terminal at the other end of the battery. I won't say it is foolproof, but it comes close. Check that the new batteries work by pressing the button. The green LED should come on. You can either now use the unit to purify water or just leave it alone. After a little while (about 15 seconds) the microprocessor will get tired of waiting, flash the red LED once and then cancel the operation.

If you are going to store the unit in the drawer for a long while between trips you are advised to take the batteries out during storage. I found the unit does draw a few milliamps when turned 'off.' This is because the microprocessor is running all the time, obediently waiting for your next command. This takes power. It is easy to take the batteries in and out between trips. The metal screw on the cap engages with a metal nut on the body (rather than plastic), giving the fastener a long life.

Steripen - 6 SteriPEN Solar Charger, open and shut, showing solar panel.

Solar Charger

The SteriPEN Adventurer will also take two rechargeable 3 volt CR123A batteries, but recharging these requires a special recharger. I have not seen any suitable generic rechargers on the market, but SteriPEN sells a solar-powered recharger for these called the SteriPEN Solar Charger. The charger's case will also protect the SteriPEN Adventurer and comes with a foam cover (not shown) that can be tied onto the top of your pack. The company says the Solar Charger can recharge a pair of the CR123A cells in about 2 days if the sun is good, but if you recharge the batteries every day it certainly won't take that long to top them up. For instance, if you have treated a few litres of water in the evening it should charge up with an hour or two of reasonable sunshine the next morning. I am not sure how one tells when the batteries are fully charged this way, but I gather the Solar Charger won't hurt the batteries.

This is an interesting concept, but the empty Solar Charger weighs 160 grams (5.64 oz) while a pair of spare batteries weighs only 30 grams (1.06 oz). Each pair of rechargeable batteries will treat about 50 litres (100 pt) of water. The extra weight of the Solar Charger seems an unnecessary burden while walking - in general you would be better off taking spare batteries. I have yet to consider giving the Solar Charger the 'UL treatment' to reduce its weight for very long thru-hikes - that would of course completely void the warranty.

The Solar Charger can also be driven by a universal plug pack from the mains, and this option is far more useful in my opinion. The plug pack can take anywhere from 90 volts to 240 volts, which means it can be used around the world. (Australia, where I live, uses 240 volts). The plug pack has pins for an American wall socket, but adapters can be bought. The plug pack connects at the hole in the side of the Solar Charger shown with the red arrow. There is a red LED beside that hole: this glows brightly while charging, and dimly (if at all) when the batteries are fully charged. I guess it measures the current flow. This option seems to me to be the one I will use most of the time.

The Future

Frankly, I think that disinfection by UV has enormous potential for outdoors use. The current 'wand' may be a little heavier than we would like, and certainly the drain on the batteries is fairly severe. Within a few years I would hope to see suitable UV LEDS being available, and I am sure the company will be very eager to release an LED-based wand with ten times the battery life, running off two lithium AA cells. When this happens I want to see the UV light shining downwards into the depths of the bottle rather than out sideways as it does now. I can dream - in the meantime this unit works fairly well.

Ideally, when the new unit is introduced a new lighter solar panel might accompany it. This should be a flat unit consisting of just the solar cells, with a power lead coming out and a small socket on the new wand. That way you could recharge the cells in the wand while you walk.

What's Unique

  • No chemicals - no taste (feature shared with Aquastar unit)
  • No long waits (feature shared with Aquastar unit)
  • Lightest UV treatment unit on the market
  • Comes with field recharger

Recommendations for Improvement

  • Move to UV LEDs
  • Have the UV light shine downwards into the bottle as well as sideways
  • Reduce current drain
  • Switch to two lithium 1.5 volt AA or AAA cells
  • Lighter Solar Charger panel, scrap the case


  1. eg Chlorine dioxide at 5 C (41 F) against Giardia and Crypto.
  2. Vendors of different chemicals may try to dispute this, but that's what comes out of independent academic research.


"SteriPEN Adventurer Water Purifier REVIEW," by Roger Caffin. (ISSN 1537-0364)., 2007-02-28 03:00:00-07.


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SteriPEN Adventurer Water Purifier REVIEW
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Brian James
(bjamesd) - F

Locale: South Coast of BC
Re: SteriPEN Adventurer Water Purifier REVIEW on 03/02/2007 10:56:12 MST Print View

I think these things would pay for their own weight by reducing the amount of water you carried. If you can treat in 2 minutes total, that means you'll be able to drink an extra litre by the end of your rest or lunch stop. 1 litre is 35oz off your back when you get back on the trail.

With Aqua Mira, the product itself weighs almost nothing but you're walking for 15-30 minutes with 1-2L (=35-70 ounces) of extra weight before you even *start* drinking.

I also think that if a water stop only takes 2 minutes and doesn't involve removing your pack, you'll do it more often. Thus if you are in terrain that crosses a water source every hour or two, you will hardly have to carry any water at all. Everyone talks a lot about reducing their base weights, but the most cost-effective weight reduction possible is your water weight.

Reducing water weight is how I justify having a hydration tube: the first two swallows pay for the weight of the tube. After that, I can drink the first litre in 20 minutes and the next litre in 40, thus keeping myself nice and hydrated as well as nice and light.

paul johnson
(pj) - F

Locale: LazyBoy in my Den - miss the forest
Re: 5000 gallon filter. 1 oz. $30 on 03/02/2007 12:33:04 MST Print View

James, not enough info there to make an in-depth evaluation. Even the "Learn More: Survival Straw" link has very little detail as to the precise construction and modus operandi of the "Survival straw".

Assuming it is as good as they say it is, then i would make only one comment about it:

it is intended as a stationary, on-demand purifying device to be used with larger bodies of water. unless one somehow adapts it into an on-the-go water reservoir system, such as an in-line filter, one isn't going to be carrying any water with them if all they have is the Survival Straw. Sure, one could fill up a water bladder, of sorts, and then periodically stop, open the water bladder, dip the Survival Straw into the water bladder and drink. However, splicing it into a home-made hydration system, using off-the-shelf components, so that it functions as an on-the-go inline filter/purifier would be a better way to go. Camel-bak makes such an inline filter (used by our Armed Forces, by the way) already. There are others also.

If you feel that my quick perusal of the Survival Straw webpage has yielded some gross conceptual errors about its nature and use, PLEASE post back and correct me. I'd appreciate it.

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Re: SteriPEN Adventurer Water Purifier REVIEW on 03/02/2007 23:04:25 MST Print View

Hi Dondo

> I was going to use a Heineken can as a purifying container/drinking mug. The diameter of the opening is about 2.75" across and the depth is about 5.75". Is this a good size to use or should I go for something shallower?
It would do, with a good bit of stirring, but wider and shallower would be a little better. The pot shown is our 1.5 L MSR Titan cooking pot.

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
re alloysafe on 03/02/2007 23:15:06 MST Print View

> I have it as part of my in-home emergency kit, and have been using it backpacking/daypacking for a few years. But I can never find any reviews of it! Either it really works or I have just been really lucky...

Sounds too good to be true, doesn't it?

I note with fascination the huge list of independent lab test reports offered as proof that it works. I also note the large amount of technical information as to how it works. And finally, I note the EPA-style %reduction figures quoted for all the bugs.

Much too good ...

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Freezing Conditions on 03/02/2007 23:20:31 MST Print View

Hi Brett

> have only had the chance to take the Steripen on one 3 day trip (in which the temperature never broke 20F and went as low as 8F). I found that the battery performance did suffer, and it was necessary to warm the unit up inside my jacket before treating water to be able to run a full cycle. My thought is that at a low enough temperature the batteries have difficulty generating enough voltage to satisfy the Steripen.

I believe the company does recommend warming everything up just as you said.

It may be very helpful to remember that, apart from the Energiser e2 lithiums, ALL the rest of the lithiums have a water-based electrolyte and, like alkalines, they all freeze up in the cold. They won't work below freezing!

(The e2 batteries don't use water and will work, with decreasing performance, down to -20 C or something like that.)

John Garberson
(Montana) - F
SteriPen and UV Transmission on 03/03/2007 09:58:09 MST Print View

Apparently, the water container blocks damaging UV from the SteriPen user. Yet, there is a generally successful method of using solar UV to treat water in glass or plastic bottles, . So, one party says UV can't go through the plastic/glass to get out, the other says UV goes through the plastic/glass to get in...? Are we talking different UV wavelengths here? Or angle of incidence? I don't want to revisit my high school me out. :)


paul johnson
(pj) - F

Locale: LazyBoy in my Den - miss the forest
Re: SteriPen and UV Transmission on 03/03/2007 13:28:13 MST Print View


SODIS does work - it is generally recommended that SODIS be allowed six hours to perform its disinfecting work on non-turbid water. Is it UV-A, UV-B, or UV-C that is doing the work. Frankly, i don't know, but i bet Dr. Caffin could tell me/us. I think it takes so long b/c the container (glass or plastic) does work pretty well to prevent UV wavelength light from penetrating.

Practically, enough UV-C is prevented from exiting the container during purification, with Steri-Pen or AquaStar that it apparently/supposedly/hopefully (you pick the right word) isn't a problem. Me? I don't look at it when it's on.

I've always disagreed theoretically with the UV can't get out/through theory. Why?

1. other's experience, viz. SODIS, as you mentioned

2. my own experience. when i was a senior & a grad student, i would prepare all of the media and run/teach the Microbiology labs at the College i attended (now an august University!!) as part of a paid Fellowship. Each semester, in about the second lab, i would have the students conduct an experiment.

We'd innoculate petri dishes containing agar and place them on a shelf in front of the close glass windows (sunny or cloudy - no matter). I'd have a control left behind some equipment in a shaded area. We'd start removing them beginning after 20min exposure and working our way up to 2+ hours. I'm really sorry, but my "old-timers" is acting up and i'm forgetting the longest period of time - somewhere b/t 2 and 4 hrs, IIRC. Then, after 24-48 hrs incubation at 37C (body temp), we examine the petri dishes for bacterial growth. The control petri dish which was in the shaded area for the entire period of time ALWAYS displayed growth. However, the longer a petri dish was exposed to the sunlight shining through the closed windows, the less growth they had. At some point, again, i must apologize, i've forgotten the exact point, in terms of minutes of exposuret to the sunlight, at which no visible growth occured, but there were always those that showed no growth that had been exposed longer.

Oh, i should add also that besides the closed glass windows, the plastic petri dishes had their tops on them too!!

UV (not sure what "band", A, B, or C, but maybe one of the Docs who participate in these Forums will be kind enough to Post and tell us) is thought to cause cataracts later in life. So, I don't stare at my container when I use a UV-C purifier. Of course, we probably get a lot more UV from the sunlight - hence, the need for a good pair of sunglasses.

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Re: SteriPen and UV Transmission on 03/03/2007 14:27:44 MST Print View

Hi pj

> SODIS does work - it is generally recommended that SODIS be allowed six hours to perform its disinfecting work on non-turbid water. Is it UV-A, UV-B, or UV-C that is doing the work.

From Wikipedia (faster than typing myself!):
Sunlight is treating the contaminated water through three synergistic radiation mechanisms.
UV-A (wavelength 320-400nm) which react with oxygen dissolved in the water produces highly reactive forms of oxygen (oxygen free radicals and hydrogen peroxides) in the water. These reactive forms of oxygen kill the microorganisms.
UV-A also interferes with the reproduction cycle of bacteria by damaging their DNA
Infrared heating the water. If the water temperatures raises above 50°C, the disinfection process is three times faster.
The combined effect of all three mechanisms is greater than that of each individual components.

The SteriPEN Adventurer uses UV-C to kill the bugs. Much shorter wavelength, more energetic photons.

paul johnson
(pj) - F

Locale: LazyBoy in my Den - miss the forest
Re: Re: Re: SteriPen and UV Transmission on 03/03/2007 16:59:00 MST Print View


Many thanks. UV-A...this answers a lot of questions and explains a lot of things. I can now accept what the Mfrs claim, viz. that UV-C doesn't escape. UV-A is probably the wavelength band that was also involved in producing no growth in that simple Microbiology lab demonstration.

BTW, the nobel prize winning physicist, Richard Feynman claims that he was the only human to get a unobscurred view of the first nuclear detonation. While others used *VERY* dark goggles to view (for fear of the large amounts of UV light produced by the bomb), Feynman viewed only through the glass window of an US Army jeep, since as he explained it, he knew that the window would stop the UV light from damaging his eyes. I've never read that he developed cataracts, though he only lived to be about 70yrs of age, IIRC. I guess the UV produced must have been mainly in the shorter UV-C wavelengths??? I should have remembered Feynman's account of the incident, and incorporated it into my thinking on this subject. I guess the viewing distance was also a factor (inverse square principle of radiating energy) for any amounts of UV-A and UV-B produced.

"I learned very early the difference between knowing the name of something and knowing something." - Richard Feynman [this quote seems to have some application to this particular subject and my lack of proper understanding on which band of UV comes into play both in SODIS and the little demonstration in Micro lab.]

Roger, if you've never read Feynman's little autobiography "Surely you're joking Mr. Feynman" [subtitled "The Adventures of a Curious Character"], you should borrow a copy from the local library (even my little town's library had it). It's a great little read which, yrs ago, I couldn't put down until late at night when i finished it. I've read it twice, i enjoyed it so much.

Edited by pj on 03/03/2007 17:16:01 MST.

Rick Dreher
(halfturbo) - MLife

Locale: Northernish California
UC C transmissivity on 03/03/2007 17:33:15 MST Print View

I found this note in SteriPEN's FAQs:

"While very few materials are transparent to UV-C, there are a small number of uncommon materials that are. These include optical grade quartz (the SteriPEN™ lamp material) and a few fluoropolymers in the Teflon family – both unlikely materials to be used for drinking containers."

Interestingly, they also note the air/water interface is an effective UV reflector.

If all that weren't comfort enough, we also have the inverse square law working in our favor. It would probably take a lot of effort to receive eye damage from one of the UV treatment gizmos. (Staring at the bare tube, perhaps?)

Thomas Jamrog
(balrog) - F

Locale: New England
Batteries for Steripen Adventurer on 03/04/2007 05:01:55 MST Print View

Surefire brand = 12 for $20.00

Regarding the LLBean deal . It is correct. Surefire 123A 10 year shelf life . 12 for $20. I bouight two boxes in the store yesterday. The salesman says they sell out very quickly, as a single battery ( while a named brand ) sells for $9 each! They are not in the Freeport, ME Main store, but in the Hunting and Fishing Store. As always , if you are not happy, bring the rest of them back with the slip and satisfaction guaranteed!
Tom Jamrog

John Garberson
(Montana) - F
UV behavior on 03/04/2007 09:56:09 MST Print View

pj and Roger -- Thanks!!

Victor Karpenko
(Viktor) - MLife

Locale: Northern California
Re: Batteries for Steripen Adventurer on 03/04/2007 11:23:58 MST Print View

Here are a couple of other sources for cheap batteries in case you don't have access to LL Bean

Surefire 12 for $21,_SureFire).php

and with toooo many other choices

Frank Ramos
(frprovis) - F
steripen and helminthes on 03/04/2007 20:40:07 MST Print View

Roger Caffin writes: "But more importantly the presence of a small amount of dirt or organic matter in the water will not greatly affect the operation of UV light." However, Natick labs gave a bad review of the steripen because it doesn't work in turbid water:

I have said this before, but I will reiterate. The primary threats to hikers from water are (a) poisonous chemicals, such as AS (the spell checker says that the metal with this chemical symbol is profanity) or the toxins released by algae blooms (b) helminthic parasites. A healthy adult with a normal immune system will suffer no more than minor distress from the protozoa or virus found in North America or Europe. Some type of of bacteria from in North America and Europe, such as particularly nasty s trains of e.coli might kill a child, but they are unlikely to kill an adult. All viruses, bacteria and protozoa found in North America and Europe can be shaken out of the body with relative ease and pose no long term danger to a healthy adult.

Chemicals can kill, but these are a minor consideration other than in the desert.

Helminthes, on the other hand, are a real danger. Anywhere there are canines (dogs, wolves, foxes, coyotes) there is the potential for hydatid cysts from echinococcus granulosus tapeworm. This can cause very severe illnesses. Currently, this tapeworm is common in all arctic regions (Alaska, Canada, Siberia) where it cycles between wolves and caribou/deer and similar prey. This tapeworm is also very common in the Alps, where it is carried by a combination of foxes and small mammals such as mice and voles. This tapeworm is/was very common in many sheep-rearing areas, such as Iceland, New Zealand, Australia, the entire Mediterranean area, Patagonia, where it is carried by a combination of dogs and sheep. The cycle is completed when dogs are allowed to eat the entrails of slaughtered sheep. This is not done in the United States or most of Northern Europe, and hence the disease is not common there. But there is nothing that says these worms couldn't be introduced and then be perpetuated by coyotes/wolves eating raw sheep. Supposedly these worms have been eradicated recently in New Zealand by a long campaign of veterinary care of the sheep.

Anyway, if you are hiking in any part of the world where there are canines, meaning all of North America and Europe, there is the potential for very dangerous helminthes in the water. Perhaps not now, but these worms could easily be introduced accidentally, such as by wolves migrating down from the Arctic into temperate North America.

Hydatid cysts are a major health problem in the poor sheep-rearing countries of the world, such as Turkey. The cycle is as follows. Unvaccinated sheep-dogs are carriers of the worms, the worm eggs come out in the dogs intestinal output (I tried to use the technical word, but the spell checker says this is profanity), little children playing around the dogs get the eggs in their mouths, the eggs hatch and burrow into the body where they form cysts. These cysts grow slowly and after a dealy of about twenty to thirty years, the person has major health problems. Treatment is quite risky, especially if the cyst is in the brain or heart.

I have been unable to find information as to the probability of ingesting worm eggs in water. It is certainly possible and the National Park Service in the Lake Superior area warns about these worms. But perhaps this is just cover-your-ass behavior on their part. I suspect the likelihood is much greater than commonly thought, and the reason we don't hear more about these worms is that there simply aren't that many people in the backcountry and the damage take 20-30 years to develop and it takes a trained physician to even recognize that the damage is due to worm and not something else. In Turkey, where hydatid cysts are common, physicians knows to suspect worms when someone in their 30's shows up with all sorts of strange symtoms. I'm not sure if doctors elsewhere are so informed.

Worm eggs are ultra-tough. Ultraviolet light has no effect on them and neither do chlorine, chlorine-dioxide or iodine. The only way to avoid ingesting worm eggs is to filter the water. Luckily, the worm eggs are fairly large, like 15 microns and up, so anything which screens for giardia will also screen worm eggs.

There's tons of information on the internet about worms, but very little about the probability of encountering such worms in places like Sierras or Appalachians. However, there are wolves, foxes and/or coyotes in these places, and thus there is the potential for a problem.

Echinoccous granulosus is just one type of helminthic parasite, but probably the biggest risk for backpackers. There are many other helminthes, all of which produce eggs which are fairly large but immune to UV and chemical treatment.

John S.
(jshann) - F
Re: steripen and helminthes on 03/05/2007 09:05:53 MST Print View

Frank said, "I'm not sure if doctors elsewhere are so informed."

Oh ye of little faith. I think most docs in the USA will diagnose it in short time by serology or ultrasound and biopsy if needed. I've had only one case, but it was already suspected by the neurosurgeon and radiologist before the biopsy ever came to me. They were right.

I'd say the probability of ingesting worm eggs in the USA is low. Heeding the warnings at Isle Royale NP would be smart. The primary threat to hikers is a motor vehicle accident on the way to the trailhead.

While echinococcosis can cause a lot of grief, most of the cysts (hydatid cysts)are solitary, occur in the liver and most are asymptomatic at the time of diagnosis.

Gene .

Locale: New England
Re: Re: steripen and helminthes on 03/05/2007 16:21:19 MST Print View

Oh great John, that's consoling,...."While E'..can cause a lot of grief, most of the cysts are solitary, occur in the liver, and are asymptomatic at the time of diagnosis."

Yeah, and then what? I had severe liver pains the past few months and sure enough after an MRI of my liver they found a cyst in there; but did nothing to treat me after telling me so?!?

Let me know which doctor(s) are 'on their game' because the one treating me apparently cut this class in med school....

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: steripen and helminthes on 03/06/2007 01:59:17 MST Print View

Frank wrote:
>Roger Caffin writes: "But more importantly the presence of a small amount of dirt or organic matter in the water will not greatly affect the operation of UV light." However, Natick labs gave a bad review of the steripen because it doesn't work in turbid water:

Well, yes, but I think Natick and I are talking about seriously different levels of contaminant!

The first problem with 'turbid water' is that the suspended matter, either organic or clay, will absorb a lot of any oxidant, rendering chemical treatment doubtful, and secondly any filter used will quickly block. If you HAVE to use such water, I suspect that boiling may be your only solution.

I have drunk stinking stagnant water once, when the creeks were all dry and the only water was underground in a pig-wallow in the creek-bed. It tasted awful!*! We survived.

Helminthes - yeah, bad stuff.

John S.
(jshann) - F
Re: Re: Re: steripen and helminthes on 03/06/2007 07:42:18 MST Print View

I hear ya Gene. Most liver cysts are not parasitic and are incidental (and benign) findings while investigating other patient complaints.

More on liver cysts...offtopic I realize.

eric levine
(ericl) - F

Locale: Northern Colorado
Batteries on 03/13/2007 09:34:36 MDT Print View

PJ has already posted my fav. links, but here are some more. I've ordered from all of these, not just browsed.

I believe these are the new 2nd generation NiMH that don't have the big hidden 'wort' of 1st gen. namely, terrible self discharge. Ray o - vac is marketing similar already under the trendy "Hybrid" name. The last thing you need is to hang on the hilltop to see a great sunset on your informal day hike, only to dig out your flashlight and get 2 minutes out of it. (of course, the spare NiMH's in your pack will get you a total of 4 minutes)

2. For HiMH, the best deal and REALLY good charger I've found is the La Crosse 900 ( 900_battery_charger.php) Besides the all important ability to charge batteries singly, it will measure the capacity & also has a rejuvenate mode.

3. Most LED lights will work with rechargable lithiums, but some unregulated lights may not.Tenergy makes a volt limited 3v rechargable lithium which should be safe in most applications.

4. I own a bunch of 123's but really favor rechargables whenever possible due to savings, predictability when topped off, and most important, the environment.

James Pitts
(jjpitts) - F

Locale: Midwest US
Steripen on 03/13/2007 13:47:30 MDT Print View

How do you treat the threads of the container? They get untreated water on them when you dip the container in the water source. With AquaMira, after you add the oxidant, you pour some treated water into the cap and over the threads. How can you treat the threads with the AquaStar? This seems like a pretty big hole in this treatment method to me.