I really wanted to love it, I even stood up for it on Back Country Post Forums, before given it a real test. The Grayl Ultralight is a new water filter and purifier that works almost like a coffee press. For a quick and dirty of how it works check out their video (Or read my first impressions here):
The Grayl Ultralight intrigued me and I was excited that Grayl was gracious enough to give me a free purifier to test 6 days on the High Sierra Trail to Mt Whitney. Before I got out on the trail, I did some in home tests and it worked great. It was simple, sturdy and filtered water quickly and easily. My first impressions of the Grayl Ultralight were superb!
But then I took it out on the trail, and filtered water from creeks, rivers, and Mt Lakes. Now all of these water sources on this trip were not very silty and the water was very clear. Unlike my Grand Canyon trip where I was filtering water from the silty Colorado River. Basically all the water sources I hit on the High Sierra Trail should not have been to difficult for any water filter to cut through.