Not sure this is the right forum,, move if needed. I'm either hiking in Estes Park, Colorado or will end up near Jackson Hole again in May. I'm going to try to do more all day fly-fishing and need to lessen my weight - will be carrying waders, food, etc. I've been looking for a good straw filter. Also, it doesn't look like any of them really kill viruses, is that necessary for the USA or is bacteria and giardia enough?