>Am I being paranoid? How do you deal with those? I would like to know what this group thinks.
The good old days--when we carried our Sierra cups and drank from every little stream we passed and never worried about carrying or disinfecting water--are gone. The Jardines drink way more water in the field than I ever will, but I just can't bring myself to drink raw water any more. My brother-in-law still suffers from a bad bout of something (giardiasis?) many years after the original attack. And since I'm also providing water for my 3- and 1-year-old kids, I'd hate even more to have something affect them.
The simple solution for me is that since we mostly day-hike in Hawaii, I carry 3-5 liters of water for the day. My base pack weight is about 15 pounds, plus 10+ pounds of water and food and 20-30 pounds of kid. But soon I'll be backpacking again and I won't be able to carry enough water. We have a nasty bug here in Hawaii that causes leptospirosis, which kills several people every year. The bacterium can wiggle through a 0.2u filter, so even a good water filter isn't sufficient. I carry Katadyn Micropur MP1 tablets in case we run short, along with a McNett 2u straw filter to stop Crypto and Giardia (no way I can wait 4 hours for iodine or chlorine to get the cysts).
I tried a Katadyn Micropur MP1 tablet by just dropping it in my 1 liter Nalgene. After 20 minutes I tasted it; it was nasty and burned slightly. I wasn't impressed. However, a few months ago I used a tablet on the trail, and after 40 minutes of hiking, the water tasted like...plain water! Evidently the sloshing made a big difference compared to just sitting on the counter.
The chlorine (or iodine) still only gets the bacteria and viruses, leaving cysts (unless you wait for hours). The straw filter works fine for just me, but doesn't cut it for the kids or for camp water. I'm loathe to carry a filter (my Katadyn Pocket isn't exactly a lightweight) so I'm considering a completely different solution.
The Hydro-Photon SteriPEN UV-C water purifier ($150) http://www.hydro-photon.com/ weighs 6.5-8oz including batteries. I thought that would be the best solution, since it weighs less than any 0.2u water filter, but then I saw the AquaStar UV-C water purifier ($100) http://uvaquastar.com/ . Weight is 3.1oz including (alkaline) batteries, not including the required wide-mouth bottle (e.g., Nalgene). The UV-C light messes up the DNA in living organisms, which means it kills or deactivates viruses, bacteria, protozoans and cysts. It does so quickly: one liter in one minute, or thereabouts. That means you can stop at a stream, zap a liter, and starting drinking it right away.
I haven't bought one yet, but either of these would seem to be the best solution for my needs. Since I usually carry a widemouth bottle for backpacking anyway, the AquaStar is certainly the lighter option. Prefiltering mucky water is required; the water must be clear for effective purification.
One problem with the UV-C purification, unlike chlorine or iodine, is that it doesn't purify the water in the bottle threads or hose. So if you're paranoid enough to worry about that, then you need to work out some way of filling the bottle without getting the threads wet, or wipe the threads dry before transferring the purified water out of the bottle.
I'd like to know if anybody on BPL has experience with a UV-C water purifier. I plan to buy one soon.