What’s the Best Way to Purify Water When Camping?

If you’re going camping or backpacking, you’re going to need water. How much? Plan on around a gallon a day for drinking, especially if you’re doing a lot of hiking or climbing, plus as much as 1/2 gallon for cooking, and another quart or so for some personal hygiene, like washing your hands and face and brushing your teeth.

If you’re not at a campsite that offers purified water, you’ll have to treat whatever the available water source is yourself. As delightful as a fresh mountain stream or lake might look, it’s never a good idea to drink the water you find in the wild without taking precautions. Rivers, streams and lakes in all likelihood contain microscopic pathogens that could cause severe diarrhea, cramps, vomiting and fever.

These pathogens could include parasites and viruses from human or animal feces, and bacteria like E.coli. They could make you sick during your trip, and hang on long after.

To stay safe, here are some ways to filter or purify your water.


Boiling is probably the tried and true method for purifying water. However, boiling requires a heat source, which means either a camp stove or fire, and it doesn’t necessarily filter out any particles in the water. If you’re hiking along and run out of water, it’s tedious to boil and cool water on the trail. Plus, whatever fuel you use for boiling water you won’t be able to use for cooking food. Given the many alternatives there are for purifying water, boiling shouldn’t be on the top of your list. But if you do need to boil water, pour it through a coffee filter or cheese cloth to strain out mud, stones and other particles before you boil and drink it.


Iodine or chlorine dioxide tablets or solution will kill harmful bacteria, though again, they don’t filter gunk out of the water. The upside is that they’re inexpensive and effective. The downside is that you need to wait 30 minutes for the chemicals to work, and iodine in particular leaves the water with a terrible taste. I trekked 150 miles through the Himalayas and past the Mt. Everest base camp drinking water I purified using only iodine tablets and never got sick once. But I’d probably try chlorine dioxide if I went again. NOTE: Iodine is not effective against Cryptosporidium; chlorine dioxide is. Also, do not use iodine tablets if you’re pregnant or have a thyroid condition.


Filters strain water through an internal element that captures protozoa and bacteria as well as fine particles. They’re not effective at isolating viruses, but that’s less a problem in North America than in developing countries. A filter may operate either by pumping, squeezing the bottle or sipping water through a filter component in a bottle, or via gravity. The GravityWorks filter won high marks from Outdoor Gear lab because it is fast, light, can filter a lot of water at one time and requires very little maintenance. The much smaller Sawyer Mini is another excellent option, but is less efficient. LifeStraw offers an actual straw filter that the company says you can use to suck water directly out of its source. The company also sells the LifeStraw mission, a water bag you fill and then connect to the straw purifier to remove all contaminants.


Purifiers function very much like filters, though some purifiers add a chemical component to their system. The water purifier that seems to get the best reviews across the board is the MSR Guardian Purifier. Though it’s also the most expensive purifier, the MSR rates particularly highly because it doesn’t clog up the way some other filters and purifiers do. Reports Backpacker.com, if you need to clean “bottle after bottle of the world’s gunkiest water, this is your filter.”

UV Purifiers

These purifiers expose water to ultraviolet light and can tackle protozoa, bacteria and viruses. They can work as quickly as 90 seconds to purify 32 fl. oz. of water. One big downside is that they’re not as effective in dirty or murky water, so you’ll have to filter the water before you treat it with UV.

REI offers and excellent overview of various water filter options here.

Gear Finder by Backpacker reviews specific products here.


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Alan W
Alan W.3 months ago

You left out some other great water filters and purifiers for camping. One would be the Katadyn. They have a long track record and are world known. The other would be the Berkey. Those 2 companies are my favorite.


Rob Chloe Sam N
Rob Chloe Sam N1 years ago

Good article with good information, Thanks for sharing this.

John B
John B1 years ago

Thanks for sharing the info.

Leong S
Leong S2 years ago


Simon L
Simon L2 years ago

Thank you

Tin Ling L
Tin Ling L2 years ago

Thank you.

Alex A
Alex A2 years ago

Your way to enlighten everything on this blog is actually pleasant, everyone manage to efficiently be familiar with it, Thanks a great deal.


Jim Ven
Jim Ven2 years ago

thanks for sharing.

Sarah Hill
Sarah Hill2 years ago

People have been drinking from streams, etc for thousands of years.

Jim Ven
Jim Ven2 years ago

thanks for sharing