Even crystal-clear, clean-smelling water can contain millions of tiny...
The internet is an incredible resource for information, but it's also a major source of misinformation, especially when it comes to highly complex topics. During our own research for our H2O Hygiene buyer's guide back in Issue 15, we learned that water filtration and purification is one such topic. It's somewhat understandable, since it deals with microscopic organisms and contaminants that are invisible to the human eye — a cup of water might appear perfectly clear and smell fresh, but drinking even one sip of it could result in days of agony or a trip to the hospital. There are lots of persistent myths about the subject. And even if a filter or purifier claims to deal with those contaminants, the manufacturer's claims can be surprisingly misleading.
As we mentioned in our 2016 buyer's guide, “Adequately testing the purity of water is impossible without sophisticated lab equipment and highly trained personnel. Off-the-shelf water test kits can’t possibly detect the minuscule levels of contaminants we’re dealing with here.” Since time and budget constraints prevented us from commissioning microbiological lab tests for that article, we evaluated the filters and purifiers based on preexisting test results from third-party labs. While the buyer's guide revealed some clear pros and cons for each product, we still would've liked to delve deeper.
We recently came across a new article from Widener's Guns, Ammo, & Shooting Blog, titled simply Survival & Backpacking Water Filter Tests. After reading this article and its “Epic Water Filter Test” segment, we can say it's easily one of the most comprehensive we've read on the subject, and an outstanding overview of water filters and purifiers.
The lengthy article touches on many of the points we wrote about back in 2016 — the hazards posed by various contaminants, log reduction, and the importance of demonstrating compliance with NSF/ANSI standards. Better yet, Widener's collected water from three contaminated sources, passed this water through 17 filters and purifiers, and had the resulting samples tested at BCS Laboratories according to “EPA purifier protocol and WHO/NSF purifier test standards.” That's a ton of work, and we commend them for it.
The conclusions of the article are fascinating. The authors compared the results of their tests to the manufacturers' claims, and gave each product a rating of Pure, Clean, Cloudy, or Murky based on the number of inconsistencies they found. Some of the cheaper filters did surprisingly well, and some of the more expensive ones didn't. Several companies omitted important information, and one was said to use “misleading marketing tactics to trick consumers into thinking it offered more protection than it actually does.”
If you're at all interested in learning more about water purification, we'd encourage you to set aside half an hour to read the full Epic Water Filter Test here: wideners.com/blog/water-filter-tests-for-survival