I'm looking forward to a 5 day kayaking sojourn, complete with wilderness camping!!!! I'm starting to get my gear together and am working out to make sure I am set for the longer mileage days. I'm also excited because I will be encountering some small whitewater and rapids...looks like fun to me!!!!! Has anyone here used a water filtration system to make stream water safe to drink? There are several on the market, many suggestions online but I'd rather hear from folks who have used them and can point out the ups or downs of what they have used. Thanks!