I don't spend time in the outdoors like most of you do, but I do carry a half dozen chlorine dioxide tabs and a water transport bag in my wallet... my major concern is "boil order" for water main burst or contamination with a sewer line... so I opted for the .1 micron Sawyer 5 gal bucket for home... backed up with calcium hypochlorite/Clorox... just a lot more convenient for an old guy