Mark - what do you think it was that made the pen not work in the alpine water? I'd love to know, and I'm sure the folks at steripen would too!

As already mentioned in this post, the SteriPEN uses UV light to inactivate E. coli bacteria, virus, but has been found to be less effective on the larger protozoa (i.e. Giardia & Cryptosporidium). The intensity of the UV lamp needs to emit around 240-280 nm of UV radiation to effectively treat water. Treatment is not occurring if the lamp is not emitting in the noted range and can be further diminished if the water is turbid and/or the glass enclosing the lamp is dirty. Suspended matter in turbid waters will shield crypto/giardia oocycts by absorbing and/or reflecting the UV radiation. For this reason, I would personally use the SteriPEN in combination with chlorine dioxide tablet as secondary treatment to ensure all microorganisms have been inactivated. It is the only way to ensure all pathogens have been eliminated from the water. This is the principal used to treat surface water supplies in the US. It only takes one of these micoorganisms to ruin your day.

It worked pretty darned well but one time when I was using it I stuck it in a little too far and now it doesn't work. Cool product but a bit unreliable.

en.wikipedia.org/wiki/Ultraviolet

some interesting reading on the various forms of UV radiation. Its actually effects on DNA and some other things I didnt realize about sunscreen and melanin production etc.

Mine worked great for all of two whole weeks of a 3+ month trip through S. America. Suddenly quit working; no apparent cause. Tried all the trouble-shooting ideas to no avail. Luckily I had Aqua Mira as a back-up. I have since heard similar accounts, for what its worth...

I bought the Steripen Journey for a car-to-car Direct Exum in a day climb up the Grand Teton last weekend. Fast and light was a necessity and since there were several water sources along the way, it seemed a sensible alternative to carrying the several liters of water necessary for such a long and serious pursuit (7,000 ft elevation gain, 15 miles of hiking, six pitches of 5.6-5.7 roped climbing and another 1,500 ft of 5.5 climbing which we soloed unroped, and then the descent).

The unit seemed to work when we tested it at home but when we NEEDED it, at 4:15 am and 4.1 miles in at 9,000 ft., the light would quit after a few seconds and the battery failure icons would show. We tried warming the batteries (it was mid 40's Fahrenheit, not even cold), removing them and cleaning the contacts, replacing them, warming them more... no use. Fortunately I brought iodine as a backup and had to use it or we would have had to bail on a climb we have planned for weeks and were in the middle of. Later in the day when the weather warmed up even further, the Steripen STILL wouldn't work. We continued on and summited the Grand Teton and made it back to our car at 9:30pm, 19.5 hours car-to-car, thanks to bringing the iodine.

After returning home I tested it and it worked at 84 degrees ambient temperature, but when I put it in a 40 degree refrigerator for 5 minutes, it failed again. I measured the voltage on the brand new, stock 3 volt batteries (Energizer Lithium photo batteries) at 2.87 volts each, only 4% below their max voltage so that was not the problem. I further spent a half hour with Hydro-Photon's Tech Support Engineer today who had me measure the voltage at the probes which was 3.25 volts (apparently perfect). It is still unclear what is wrong with the unit but the fact remains that if failed during its first use in the field.

I purchased a Steripen a couple years ago. Nice when it works. The first one was defective so I sent it back and received a replacement. I have found it to work intermittently and like others have mentioned..cold temperatures don't always agree with this gadget. UV is an excellent way to kill organics in water, but trusting your health and hydration to this thing in critical situations is not recommended. Chlorine dioxide, iodine and filters (not my favorite) are more robust, reliable and get the job done. My Steripen sits in a box and that is the best place for it as far as I am concerned.

The cdc has a good review of water purification science. Some questions remain unanswered. I boil or use combo of filtration plus chlorine. www.cdc.gov/healthywater/drinking/travel/backcountry_water_t>>>

I removed some bad words about the company in my previous post... though they were all true I just had a subsequent telephone conversation with Aaron Cox from Steripen and he agreed to test a new unit out for me, using a refrigerator at cold temperatures to make sure it will work down to freezing prior to shipping it. He's also replacing the batteries so that they're new and including coupons for additional batteries as well as a mailer for me to send the old one back if and when I am satisfied that the replacement unit will work appropriately. I don't think I asked too much of Hydro-Photon to go through this trouble, but I would like to say that I am also impressed with Aaron's concern for making me a happy customer and doing the right thing.

Following is an emailed response from SteriPEN. I am now extremely satisfied with SteriPEN’s customer service. I couldn’t ask for more. I hope to have good luck with the replacement unit, and I am optimistic:

Hello Michael,
I have taken a new SteriPEN Journey from a retail package and performed the following tests:
Placed your Journey, with batteries installed, in our lunch freezer for 25 minutes. I removed your Journey and successfully completed a 1 Liter dose.
Placed just batteries, in a Ziploc baggie, in the freezer for 15 minutes. I removed the batteries and immediately placed them in your Journey. 1 liter dose complete with no frowny faces.
Placed your Journey and Ziploc baggie with batteries in freezer. I removed the batteries and Journey and immediately placed the batteries in your SteriPEN. Again, I was able to complete the 1 Liter dose with no problem.
This leads me to believe that you will not have the same problems with your new Journey as you did with your original.
Again, I am sorry for the troubles that you experienced due to the battery failure of your original Journey. This is unacceptable and we will do what it takes to rectify your situation and restore your confidence in the SteriPEN.

I have had your new Journey repackaged and shipped to your address via UPS 3 Day Select.
UPS will send the tracking number to your e-mail around 5PM tonight.

Thanks for the opportunity to try and rectify your problems.
Best Regards,
Aaron Cox
Customer Support
Hydro-Photon, Inc.
207-374-5848
www.steripen.com

Michael,

I wish the tests had included very cold water.

Thread res but figured why start a new one.

So those who use the Steripen pre-filter, how do you rinse out or clean the pre-filter? If you swish it in the water source, then the rear end of the filter is now contaminated, no?