I just came back from a 60 mile hike including climbing Mt Whitney (beautiful place BTW <img src="/images/graemlins/laugh.gif" alt="" />), and I learned something about the Hiker water filter by Katadyn.

Hiker has two tubes that can be attached to it: inlet and outlet. What we did on our hike was simply wrap both tubes around the body of the filter and stuff it in the soft case provided. Now, it may sound pretty obvious to others, but for some reason it did not occur to us at the time (probably altitude sickness clouding our judgement). If you have both dirty and clean tubes in the same place - cross contamination will occur. And it did! <img src="/images/graemlins/frown.gif" alt="" />

Somehow I escaped the wrath of bacteria, possibly because I had a Camelback, which I connected directly to the filter, but my friend came down with a relatively strong intestinal sickness (nausea, vomiting, diarrhea) after drinking one of the last batches of water. We immediately desinfected our water with Micropur tablets, but it was too late for him.

Moral of the story: make sure to separate your dirty and clean tubes on Hiker water filter. Probably put a clean tube in a separate ziplock baggie.