Are all water filters created equal?

In the last few years, the number of people making product recommendations has exploded, due in part to the growing number of “survival/prepping” podcasts/blogs/YouTube channels/etc. Which is great for the manufacturers & suppliers, but not so great for the consumer.


Because not everyone who makes a recommendation on a particular product is very knowledgeable in its usage and/or specifications, and because of that, they may not always give you the most accurate, informed purchasing recommendation on what they think is “the best” you should get.

For example, I was listening to a podcast episode whilst enjoying my morning coffee, and the individual was reading off a list of recommended products to purchase for your favorite person as a gift (some were pretty cool, and others were just gimmicks, but that’s a post for another day.) Included in the list was a particular water filtration device, and they listed a number of false “facts” about this particular filter. While they were reading the list, they came across a few words they had obviously never encountered before and couldn’t pronounce. Not a big deal, you say?

Cryptosporidium should be a common word in your vernacular when you’re supposedly teaching people about survival, right along with Giardia lamblia and Legionella.

As I continued listening, my mind wandered off and began recounting how often over the past year I’d heard the very same recommendation being made from other people, supposedly knowledgeable in the industry, and the rough number my brain came up with was alarming. It occurred to me that people seemed to be regurgitating the same information they’d heard from someone else, and hadn’t bothered to do their own research on this particular product. Kinda like all of the YouTube videos that show the same skill over and over by thousands of people who probably haven’t ever done it “for real”, aside from making the video – another post for another day on that subject.

So, in order to provide the folks reading this with better information about water filtration devices* currently on the market, without predujice, I give you these golden nuggets of (hopefully) life-saving information. I’m not endorsing any manufacturer, nor am I picking on any manufacturer; I’m providing information only. In the interest of full disclosure, I own more than several filters, including Sawyer, LifeStraw, Katadyn, and others.

1. Not all filters filter everything.
Cryptosporidium, Giardia, E-coli, Legionella, and Hepatitis are just a few of the nasties found in water that can make you really uncomfortable. If you’re in a true emergent situation, dehydration is one of the side-effects from almost all of those things above that has the potential to make it end pretty quickly for you. Some filters DO NOT filter all of the Big Three (bacteria, viruses, and protozoa.)

For example, LifeStraw will only remove bacteria and waterborne parasites. Source:

2. Some filters need to be tested periodically.
Some filters need to be tested every so often to make sure they’ll still function as designed/advertised. Other filters aren’t designed to be field tested or cleaned, or even at home prior to their use. Hollow fiber filters are an example of this. Some filters can be both tested AND cleaned in the field.
You test your other gear every so often, why not your water filter?

3. Not all claims of performance are true.
Claims of being able to filter “1 Million Gallons, Guaranteed”, or being “certified by the EPA” are not accurate. Some claims stating “Exceeds EPA recommendations for removal rates” have also found to be a marketing exaggeration.

Want proof? Have a look at the findings brought against Sawyer in January of 2015 for making false claims in their advertisements. There may be others, but I haven’t looked too hard for any.

4. Do your own research.
While a particular filter/purifier may be compliant to EPA standards (see the resources below) by removing certain foreign bodies, not all filters are created equal. Look for “Tested and certified to NSF/ANSI Standard 53” or “NSF/ANSI Standard 58” for cyst removal/reduction, for both Crypto and Giardia.

Points to Ponder
Some filters do a great job at removing protozoa, but may not filter bacteria.
Carbon Fiber units are difficult or impossible to inspect for damage/effectiveness.
Ceramic units can crack if dropped or frozen, rendering them useless.
Some units DO NOT filter, only purify (such as SteriPen.)
Pay close attention to the MICRON measurements in the product specifications.

The Safe Drinking Water Act
Table of Regulated Drinking Water Contaminants
EPA’s drinking water regulations for pathogens and indicators
CDC Guide to Water Filters
How are pathogens and indicators removed from my drinking water?
Sawyer – False advertising claims on product specifications (Ruling) (PDF)
US National Library of Medicine, National Institute of Health report (PDF)
Effect of Chlorine on Giardia lamblia Cyst Viability


*Yes, they’re actually water “purifiers”, but most of the current devices perform both functions except the SteriPen.

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