A FOLLOWUP on the HTI Hydropacks I mentioned earlier: So I put one in a pot of water and 12 hours later it had filled. Tasted like room-temperature Gatorade more or less. Was easy to use. I didn’t test it on contaminated water because I was too busy to add dirt. I can see why a pallet-load of these would be useful disaster-prep for a small city or organization. Some readers suggested that a Katadyn filter would be better, and of course they’re right. But these are easy to store and portable. They’d do well in a backpack or car bag, too.