Mark purifies water at the first shelter: "All the shelters along the way are situated very close to water sources. Most of them are natural springs. Many bubble directly from the ground so quite a few of the thru-hikers we met didn't bother purifying it. Jeremy and I decided to err on the side of caution and purified everywhere we stopped."

The purifier we used along the trail is the First Need Deluxe which was donated by General Ecology. After using this purifier, I would gladly pack the extra weight of this one, rather than risk using any of the others on the market. Along the trail we saw people recovering from Guiardia, and others fumbling with purifiers and filters that they couldn't get primed. The First Need Deluxe never offered us one minute of trouble and pumped water at an amazing pace.