Informative article on giardia lamblia... made sense to me. His conclusions tallied with what I *thought* I knew, but he's done properly documented research, which makes it very useful to me. The "hot water" specifics were especially interesting (Chris and Doug are right, no surprise), and something I was interested in knowing more about. Thanks for the link. <br><br>I recently read an additional bit of giardia trivia - it may have been here - that I have not verified: Supposedly giardia cysts are sufficiently denser than fresh water that they rapidly sink in deep unroiled clear water - the article snippet was about drinking lake water in the Boundary Waters, IIRC. Hmmm. We had to chop thru the ice for water the last time I was there (wintertime) and I'm certain that a lot of folks who ply those waters (thawed or frozen) are not "good" about human waste management. Yet common practice seems to be drawing the water from the lakes and simply using it. Any microbiologists here that can comment? <br><br>Now for a similar article about our other major protozoan buddy, cryptosporodium parvum... anyone find a good one yet? I've only made a cursory check so far and am faintly skeptical of the utility of most of what I glanced at. There was one Canadian article that was pretty good -"realistically cautious" is how I would characterize it - but it didn't credit any scientific sources. The rest of what I've glanced at is pretty focused on munincipal / residential type situations (science + technology + legal = paranoia) or "you should buy our product because..." <br><br>I did find ample scientific evidence regarding the futility of using chlorine alone, but zip nada nothing scientific about iodine. CDC says that iodine will work, but it takes 15 hours to be certain against Crypto. parvum. Chlorine dioxide (AquaMira) is claimed to be effective, but again, I've not seen hard evidence yet. Am very interested in learning more about crypto. p. as it pertains to our main interests here (survival) and more directly, to travel away from the munincipal spigot... if anyone finds noteworthy info, please share!<br><br>Both these beasties (and other critters) bring me back to an earlier question - has anyone been using Chlor-floc? I'm guessing that works by floculating most (all?) the suspended solids - specifically including the bugs - and then chlorinating the super natent. Regardless, does anyone know how effective that approach is?<br><br>Regards,<br><br>Tom