The human body can survive for about three weeks without food. However, it can only go about three to four days without water.

Studies have shown that even a modest decrease in hydration (2% reduction of overall body mass) can lead to a 20% decrease in physical performance in mild conditions, and up to a 40% decrease in hot environments. In extreme conditions, one can lose up to 1.5 liters of sweat per hour!

Most experts recommend that you consume the same number of ounces of water per day, as pounds you weigh. For example, if I weigh 178 pounds, I would want to consume at least 178 ounces of water per day, during my normal daily activities. Put yourself into the wild, hiking ten hours a day and burning over 5000 calories a day and the amount of water you should be trying to intake obviously increases.

There are some sources of water, in the wild, that are pure and delicious, and I know of quite a few hikers who proudly boast that they have never filtered water on any trip and have never gotten sick. Good for them! I am not one of those brave souls. I think it is worth the short time it takes to collect and treat water before drinking it, for the piece of mind I get from doing so, regardless of the perceived water quality at the source.

There are two main ways to prepare water for consumption, and even more methods and products to implement these approaches.


    Filtration essentially strains unwanted particles out of the water. The two most common water filtration systems are sediment filters and activated carbon filters and often the two methods are combined. Sediment filters remove contaminants according to size, including most microscopic contaminants, but some, such as viruses, dissolved pharmaceuticals, and some natural but harmful minerals are too small to be trapped, and these pass through instead.

    Most filtration systems use activated carbon to filter out contaminants. Carbon filters trap carbon-based particles that attempt to pass through them. Carbon-based particles account for the majority of the harmful contaminants present in most water sources.

    Essentially filters will block bacteria and protozoa from getting through into the treated drinkable water, but NOT viruses.


    To purify, by definition, does not mean removing any or all random matter in a solution. It actually means to remove what is not wanted. So, a product that claims to purify water does not claim to make the water “pure” (like distillation or reverse osmosis); it just means that it removes what is not wanted, or unhealthy, from the water. Examples of purification methods include iodine tablets or chlorine bleach drops, boiling water, UV light like the SteriPEN Ultra, as well as chemical treatment kits like Aquamira Water Treatment (Chlorine Dioxide treatment)  and Polar Pure (Iodine treatment).

    Essentially purification will remove bacteria and protozoa from the treated drinkable water, AS WELL AS viruses.

So what is the difference?

The main difference between the two is that purification takes out what you don’t want in the water, while filtration prevents what is unwanted from entering a water system in the first place. Just to keep it confusing though, there are filters so fine that they are able to remove viruses and, therefore, are referred to as a purification devices. And, there are also chemicals that can be added to water to separate the sediment by causing it to sink, and are therefore referred to as filtration devices. Simple right?

Essentially filters will block bacteria and protozoa from getting through into the treated drinkable water, but NOT viruses, while purification will remove bacteria, protozoa, AND viruses from the treated drinkable water.


Which method is right for you?

If you are backpacking or camping in the wilderness of the United States or Canada a high quality .02 micron (or better) water filter like the Sawyer Squeeze  will be more than enough protection in almost any area where you can find fresh water.

If you are traveling in the wild internationally or even (maybe especially) in urban areas in developing countries, where the water distribution infrastructure or treatment may be compromised, using a filter along with a purification treatment is your best bet. There are also some high-end filters out there now that can block viruses as well; Sawyer’s new “foam” line is supposed to be released this year and will come in three different levels of protection: check those out here and sign up for release updates

With technologies getting so advanced and affordable there are endless combinations of set-ups to fit your specific needs.

***Final Note***

Most trail illness is the result of bad hygiene; not properly cleansing or disinfecting hands after using the bathroom or neglecting proper cleaning/care of your cooking/eating gear are usually the reasons for hikers come down with something. Then those hikers inadvertently pass these viruses onto others. Do yourself and everyone on the trail a favor and practice proper hygiene.



To see reviews of the water treatment options I’ve used on the trail check these sub menus!









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