When trekking, camping, or hiking, this tutorial on how to purify water in the wild teaches you six techniques for getting rid of water-borne contaminants from water obtained from untamed sources.

Learn how to filter water in the wild to avoid going to the doctor or spending a week or more within ten feet of the closest toilet!

The body fluids we lose when trekking in the wilderness are constantly in need of replacement; most experts estimate that we lose around one liter of bodily fluid every two hours of hiking.

But it can be difficult to get enough safe, clean drinking water into the system (see our explainer, Water for hiking: how much do you need? ), especially when our trails take us far into the backcountry and we have to replenish our water supplies by getting it from untamed sources like streams, lakes, creeks, or rivers.

While to the human eye they may seem clear, clean, and unthreatening, they may include a variety of tiny mayhem-makers that may easily thwart our goals for a pleasant, trouble-free vacation.

Therefore, for any hiker wishing to prevent a trip to the hospital or a protracted period of time on the john, understanding how to filter water in the woods – and taking the time to do so – is of the highest significance.

This article explains how to purify water in the outdoors using six distinct methods, ranging from traditional boiling to cutting-edge UV sterilization.

Why Water Purification Is Crucial

Water-borne bacteria, protozoa, or viruses are among the few things that may spoil a hiking or camping vacation quite as they can.

The most typical of them are as follows:

Giardia and cryptosporidium Two protozoa found in human and animal feces and capable of inflicting severe gastroenteritis (vomiting, diarrhea, and cramps).

In the majority of rural areas of the globe, both are common.

Amoebic dysentery and dysentery Protozoan parasites found in human or animal feces are also to blame for these.

Fever, bloody or mucous diarrhea, chills, and discomfort or pain in the abdomen are all symptoms.

Check out The Time I Died in Ladakh for a (somewhat graphic) glimpse of what a few days with amoebic dysentery looks like (opens in new tab).

Bacteria Shigella, E. Coli, salmonella, and campylobacter are the most prevalent water-borne bacterial illnesses, and they are all potentially lethal.

Viruses Hepatitis A, enterovirus, rotavirus, and norovirus are a few examples of the water-borne viruses that may be acquired by consuming water from untreated sources in the wild.

Water filtration systems cannot remove any of them, but UV pens, boiling, and certain purification pills may.

6 Ways To Sanitize Water In The Outdoors

#1. Boiling

One of the safest methods to clean drinking water obtained from natural sources is to boil it.

This is due to the fact that no disease can survive temperatures higher than 170 °F that are often present in natural water.

Water boils at 212 °F at sea level and at around 200 °F at heights of about 14,000 feet, thus when done correctly, boiling will safely get rid of any water-borne pathogens.

Generally speaking, for water to be safe to drink, it has to be on a rolling, bubbling boil for at least 2 minutes.


  • Removes viruses, protozoa, and bacteria
  • No additional equipment is needed if you’re camping


  • You can only process a very little amount of water at once.
  • Requires bringing a kind of camping stove with you.
  • Time-consuming
  • Usage of fuel
  • Hot processed water (ideal for cooking, not so much for drinking)

#2. Cleansing Pills

For hikers or campers who are attempting to keep their pack sizes as small as possible and gram counters, chemical purification tablets are often regarded as the best purification option.

A blister pack of ten tablets, which may cure up to 10 liters of water, weighs almost nothing and is approximately the size of a stick of gum.

Iodine and chlorine dioxide are the two most often used chemical treatments.

While most tablets can successfully get rid of the bulk of bacteria, viruses, and germs, iodine can not get rid of one of the most prevalent water-borne pests, Cryptosporidium, and both make your water taste awful.


  • Tiny and portable
  • Simple to use
  • Cheap


  • Does not remove our muck or sand
  • Leave a sour impression
  • A minimum of 30 minutes must pass before consuming
  • Iodine may be unhealthy for those with thyroid disorders and pregnant women.

#3. Pens That Sterilize Using Ultraviolet Light

UV rays are used by ultraviolet light purifiers to destroy viruses, protozoa, and bacteria.

The majority of versions are fairly simple to use; all you have to do is fill your water bottle (see: top hiking water bottles) and swirl the water with your purifier pen for a few minutes to make sure it is safe to drink.

The main drawback of UV purification is that you may need to pre-filter your water to remove sediment and that the pens need batteries, so you’ll need to keep them charged.

The SteriPEN Aqua UV Water Purifier is the pen we recommend most highly (opens in new tab).


  • Lightweight
  • Speedy processing
  • Get rid of all viruses and pathogens


  • Need batteries
  • Simple to defeat
  • To eliminate sediment, pre-filtering of water may be necessary.
  • Pricey

#4. Squeeze/Sip Filters

These individual filtration devices, sometimes known as “straw filters,” eliminate germs and protozoa via minuscule holes in the filter that may be as small as 0.2 millimetres.

These inexpensive, portable gadgets may be added to your water bottle or used to sip straight from a water source.

They are ineffective at processing huge amounts of water and do not remove viruses, which is a drawback.

Check see Hydration packs vs. water filtration for additional information on them.


  • Inexpensive
  • Tiny and portable


  • Do not get rid of viruses
  • Unable to handle enough water for a party or cook

#5. Motor Filters

Pump water filters are simply straw, squeeze, and drink filters with an attached pump that eliminates the need for you to suction water through the filter.

They are thus a far superior choice for processing bigger amounts of water.

Pump-style versions are efficient at removing bacteria and protozoa, like other filters, but only a select few, high-end ones can handle viruses.

Pump filters have only a high RRP, are bulky, and need regular (and labor-intensive) maintenance.

Our favorite among the lot is the Katadyn Hiker Pro Microfilter (opens in new tab).


  • Speedy processing
  • Reduces water’s sedimentation
  • Gives clean water right away.


  • Reasonably expensive
  • Filters might become clogged.
  • Large-scale filtering requires some physical labor.
  • Bulky

#6. Grass-Fed Filters

Gravity filters are the best option for basecamping or group camping.

As their name implies, they function by filtering water using gravity from a large reservoir into a container below.

The beauty of these filters is that you can sit back and relax in your camping chair as they process up to a liter of water each minute.

The drawback of gravity filters is that they are more heavier than UV pens, purification tablets, and straws.

Additionally, if the reservoir is filled with water that has a lot of sediment in it, the filters may quickly clog.

The Katadyn Gravity Camp 6L Water Filter is our preferred gravity filter (opens in new tab).


  • No stirring or pumping is necessary.
  • Very little waiting
  • The capacity to process vast amounts of water


  • Need a limb from a tree or other kind of support to hang the reservoir from
  • Very hefty and large
  • Do not get rid of viruses

How To Filter Water In The Wild Videos Suggestions From Youtube

How To Make a Water Filter In The Wild – caveman cody
Every Way to FILTER WATER in the Backcountry! | Miranda in the Wild – REI
5 Ways to Purify Water in the Wilderness – Whistle Thicket

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Written by Bob Matsuoka
Bob Matsuoka is a blogger and founder of RVing Beginner blog. He has been blogging for over five years, writing about his own family’s RV adventures, tips for people who are interested in buying an RV or taking their family on an adventure by RV.