Kalmiopsis Wilderness

Choosing the right Water Filter for Backpacking


When you head into a wilderness area you need to decide on how you will make the water you drink safe. There are (2) methods for doing this. The first is using a water filter system, and the second is using a water purification system.  Each system has its pros and cons. This article will discuss these methods so you can make an informed decision on which method to use.

The reason you need to treat the water you drink in any wilderness area is because of harmful microbes in the water.  Water filters and purification systems either remove or neutralize harmful microbes in the water.

Harmful Microbes

Some harmful microbes that you will encounter in a wilderness are:

Protozoa:  A disease-causing parasites such as (cryptosporidium, giardia).

Bacteria:  A Microorganism that becomes a parasite living off other organisms. An example is E -Coli (Escherichia Coli) .

Viruses:  A Microorganism that feeds off other organisms and replicates itself.  Examples include Hepatitis and Rotavirus.

Gila Wilderness

Gila Wilderness (NM)


Water filters remove protozoa and bacteria but they do not effectively remove viruses.  Water filters also remove floating sediments such as sand and other debris from water.  The effectiveness of a water filter to make drinking water safe relies heavily on it’s micron rating.  A micron is one millionth of a meter.

Most filter elements are made of fibrous strands.  The distance between these strands is the micron measurement.  The closer together these strands are the more microbes that filter element will remove. The smaller a micron rating the better the water filter is for removing harmful microbes.  (e.g. a .1 micron is better for filtering out microbes than a .2 micron filter is).

Most water filters for backpacker’s in today’s market are rated at .2 microns.  A .2 micron rating will filter out protozoa and bacteria .  They will not filter out viruses because a virus can get much smaller than .2 microns.

Types of Water Filters

  1. Pump Filters:

 A pump filter siphons water from a source.  Some models you squeeze others use a lever.  Katadyn and MSR are a few of the popular ones.   Most of these filters have a .2-micron rating with a few at a .1 rating. 

MSR makes a pump system called the MSR Guardian Purifier.  It is a filter and purifying system.  It is rated at .002 microns that will filter out many viruses.  I have not used this system, but it comes with a hefty price costing about  $350.00 dollars.  It is an all in one filter but the cost may defer many from buying it.  Although it is a great system there are much less expensive systems like the Katadyn Hiker Pro that are exceptional for North American Wilderness areas.

Pump Pros:

  • Easy to use
  • Can reach water sources
  • Easy to maintain

Pump Cons:

  • They can be bulky
  • Filters are expensive to replace
  • Most do not filter out viruses.


2.  Gravity Filters

 Gravity filters are becoming a popular water filtration system for many backpackers, especially if you travel in groups.  Gravity filters are exactly what the name implies.  You fill up a bag full of dirty water and hang it up.  The weight of the water pushes it through a filter.  The filter is either in the bag, (such as a Katadyn), or it is connected inline on the outside of the system, (such as a Platypus system).  Most of these systems have a .2-micron rating.

Gravity Pros:

  • They can filter a larger quantity of water for a group of people
  • less labor intensive letting gravity do the work.

 Gravity Cons:

  • Filters can clog much faster than other systems
  • The water source may make it  difficult or impossible to retrieve the water
  • They do not filter out viruses (at present)


  1. Straw Filters

 Straw type filters are very easy to use and you drink directly from the water source.  These filters are great for the backpacker on the move.  The Life Straw is one well-known straw filter.


LifeStraw (.2 Microns)

Straw Pros:

  • Lightweight and small
  • The are inexpensive
  • Easy to use

 Straw Cons:

  • They cannot fill containers
  • They do not filter out viruses (at present)
  • You have to drink close to the water source


Purification methods rely on using a chemical such as chlorine, salt, iodine, etc. They usually come in a tablet form.  They are made to kill harmful microbes.  You may choose as many do to  boil the water killing the microbes.  Purification systems do not remove the floating or suspended sediments from the water.

Types of Purification Systems:

1. Tablets/Chemicals

Micropur MP1 Purification Tablets

Micropur MP1 Purification Tablets

Using chemicals, (i.e. tablets, solutions), to treat water has been around for quite a while.  When I was in the military, we had iodine tablets to purify our drinking water.  Chemicals are very effective in killing harmful microbes.  The down side is that there is a strong after taste when you have treated the water.  This process also does not remover suspended sediments.  Much of the newer chemical processes today are much better than when I used them.  Katadyn has the micropur tablet which purify your water with a less after taste. 


Tablet Pros:

  • Very small and portable
  • Effectively kills harmful microbes,

 Tablet Cons:

  • After taste of the chemical used
  • Does not remove suspended sediments
  • Waiting period (time) to effectively kill or neutralize microbes.


2.  UV (Ultra Violet) Process

Using a UV (Ultra Violet) method to purify water is becoming popular by many backpackers traveling outside the United States for their adventures. UV does not kill the microbe but it neutralizes it preventing it from reproducing.  Thus a virus will not reproduce in your body.  A very popular system is the Steripen

UV Pros:

  • More effective on viruses than chemicals
  • No chemical after taste
  • Immediate results
  • Economical for purifying large amounts of water

UV Cons:

  • Can break easily if not maintained
  • Relies on batteries
  • Suspended sediments are not removed from the water.


3.  Boiling Water

 Boiling water is the most effective way to kill microorganisms in your drinking water. It has been around for quite a while.  It is a well-known method and used throughout the world.    It can be time-consuming and you have to let the water-cool down before you drink it. 

 Boiling Pros:

  • Least expensive process
  • It kills all organisms


  • Takes time to set up
  • You need a proper container to boil the water
  • Does not remove sediments.


Gila Wilderness

Gila Wilderness (NM)

Water filter and purification systems vary in their applications and use.  When deciding which system to use ask yourself the following (2) questions.

  1. Where you will use it? If you are going backpacking with a large group will gravity filter work better for your application then using a straw? 
  2. Is the water source easy to reach and retrieve?If the water source in a shallow tight area you may not be able to use a straw or you may not be able to retrieve it in a gravity bag.

I backpack in North America and I prefer using a water filtration system over a water purification systems.  I use a .2-micron level filter and I have not gotten sick from the water sources I have consumed.  I prefer using a pump filter, and I like that my filter system also takes out sediments. 

A pump system is very versatile for my applications.  I do not have to be at the level of the water source to use it like a straw filter.  If a water source is in a crack or crevasse I can lower the hose on my pump systems directly into the. 

I remember backpacking in Georgia, (Cohutta Wilderness), where water was difficult to find due to lack of rain. We came across a source that was flowing over some rocks.  The only way to retrieve it was to use a pump or straw.  The problem with a straw was that we could not fill our containers.  Having a pump allowed us to pump the water into a container.

I thought about having a gravity filter in my backpack for my basecamp use.  If I am near a river or stream I can scoop out a large bag of water bring it to my basecamp and let gravity do its job.  The nice thing about this is large amounts of water can be filtered using which allows you to take fewer trips to the water source. 

I will always carry a pump because a gravity filter can be time-consuming when you are on the trail or doing your daily expeditions.  I always have some micropur purification tablets in my Backpack for an emergency. They are lightweight and will get me out of a bad situation quickly.

As with many other types of backpacking gear you will decide which water system will work best for your needs.

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