We know that UV light was long ago proven to kill microorganisms in water. In fact, Gwen works with zebrafish and UV lights are used to kill things that may be in the water before it is pumped to the fish tanks. Our main concern was, "how practical is the Steri-Pen for long distance backpacking?" The Steri-Pen is marketed as a product to purify clear tap water that may be contaminated and is really meant to avoid intestinal problems following international travel. However, the larger outfitters (namely, REI, where we purchased our Steri-Pen) have picked up this product as a purifier that could be used for camping/backpacking.
We read the scientific papers that presented the results of tests on the Steri-Pen and were satisfied that the science was sound and that the product really works (As a side-note, Hydro-Photon has satisified the EPA's Standard Protocol for Testing Microbiological Water Purifiers). But, we were still concerned about whether it would work for us in the situation we needed to use it in. We decided to test the Steri-Pen ourselves. We would then be able to see just how long it took to purify the cloudy, sediment laden water we might be forced to use in the back country.
