How to Choose a Water Filter for Outdoor

By Kevin Arnold | Camping

Aug 10
how to choose water filter for outdoor

Every backpacker or camper, who frequently goes on extended trips, will tell you two things are a essential to ensure a successful trip: taking care of your feet with good shoes and socks and access to plenty of clean water. As with any strenuous physical activity, lack water can result in serious consequences; additionally, drinking water that is not proper filtered or cleaned can leave you in a dangerous situation when miles away from accessible medical treatment. Still, many do not know how to choose a water filter.

Why is Unfiltered Water so Dangerous?

Trying to carry all the water needed with you on a backpacking or camping trip is nearly impossible and a huge unnecessary weight addition. For this reason, we must look for natural sources of water like lakes, streams, and rivers. The problem is these water sources are loaded with parasites and viruses that can lead anyone who drinks from them in a terrible state.

polluted water

Giardia is the most common parasites which affects the intestines and produces violent diarrhea, vomiting, excess gas, severe abdominal cramps, and nausea. This, if not quickly treated, results in dehydration and loss of nutrients and will bring any trip to an abrupt halt. Understanding this, leads every experienced backpacker to see the importance of a quality water filter.

How to buy a Water Filter for camping or backpacking

When buying a water filter, it is important to, first, understand what you want the filter to accomplish. After that, understand your personal style and approach to backpacking.

The Water Filter or the Water Purifier (chemical tablets and products like Steripens)

There is a key difference among these two classifications and it’s based on the size of the microorganism each fight. Most people taking trips in areas like the USA want a filter because it works to remove bacteria and trash from the water. If going on a trip to an area of the world that has waterborne viruses one must look for a purifier.

Water filters work by forcing out protozoan cyst like Cryptosporidium and Giardia and the harmful bacteria like E. Coli, Salmonella, Campylobacter, and Shigella. These are in many US water sources as they have seeped into the water from things like animal fecal matter.

Water purifiers have the ability to catch viruses that are far too small for most filters to expel. These viruses include hepatitis A, rotavirus, and norovirus.

It is worth mentioning that you should think about how clear the water source is. Purifiers do not filter out debris and trash and will need additional filtering if the water source is dirty.

How does a Water Filter and a Water Purifier exactly work?

Nearly all filters come with two main parts. It has a cartridge or internal component, that has really small pores that catch debris and bacteria while allowing clean water to pass through. If the water filter rate has tremendously slowed down, it needs to, either, be cleaned or replaced.

Many of these filters have charcoal or activated carbon that filters the water, reduces contaminants like those in entering the water through pesticides, and, ultimately, makes the water taste better by removing things like leaf tannins.

Water purifiers use, either, chemicals such as iodine or UV light to kill viruses and pathogens. This takes time for the purifiers to destroy the harmful ingredients as it interacts with them. Many people do not like tablets that use iodine or chlorine because it gives off an undesired taste, as will UV lights, does not help by removing bad tasting elements in water.

Understanding the difference between the two classes mentioned above one must consider several things based on personal preference.

1- How fast do you want it to work?

Some filters work really quickly while others take much longer. For this reason, think about how much water you will be filtering. Are there multiple people using your filter?

Using tablets like iodine, often take as long as four hours while a good filter can do much more water in mere minutes. Using a pen that uses UV rays works rather quickly to ensure all harmful pathogens are killed as well. Roughly a bottle of water is usually drinkable in around 60 seconds after using a UV pen.

2- How much weight can you spare for a filter?

For the avid backpacker and camper, they know that weight is a huge factor in packing for a trip of any length of time. For this reason, some backpackers use lighter, smaller filters, tablets, or UV pens. As stated above, these purifiers and, often, smaller filters have a tradeoff of taking longer and being less effective than bigger filters.

UV pens are the exception to this, but many do think you lose a lot in the taste quality with one.

3- How much do you want to work when filtering water?

Some filters allow you to fill it up and forget about it. Not only are purifiers like this, but filters actually make a gravity version that is simply hung up and filters down from one bag to another with no work. Most filters require some form of physical work to function like with pumping and squeezing.

Some people on long trips prefer to waste the energy and take a break while water filters. Others do not like to have to stop and prefer to pump quickly and continue moving.

What are the different options available?

Pump filters 

Filtering Water

these work as you drop an input hose or tube into the water source and another into a container that can hold the clean water. Make sure not to mix up these hoses or the water and filter will become contaminated. These are convenient because it works for most water sources regardless of how shallow and allows you to filter the exact amount of water desired.

It does require work to pump. It needs to be cleaned, somewhat, after each use and is one of the heavier, larger options.

Bottle Filters and Squeeze filters

squeeze filter

The bottle form is very simple. You put water in, it filters it and you can drink it basically instantly. These are usually cheap and easily replaced.

The squeeze filter is similar but filters as you squeeze the water out rather than when you put it in. It is lightweight and cheap as well.

These do clog up really easily and are not considered quite as effective as pump filters. You are really limited with amounts because you can only fill up a small bottle worth.

Gravity Filters

gravity filter

This works as one would think. You hang one bag higher than another and gravity pushes the water through a filter and cleans it. You don’t do much work and it can do large quantities of water.

It can be hard in certain areas to find places to hang and it is a slow process. Water is not easily added into the first bag because it does not create any suction like the pump.

Ultraviolent (UV) Light Pens

Ultraviolent (UV) Light water filter

These are really handy as you simply cut it on stick it in a bottle and in 60 seconds you have water. It does not require the cleaning most other options do because it kills the pathogens that could contaminant it.

It does need batteries and they can run out and leave you in a bad place. It does not work well for water that starts out cloudy because it can’t filter. It does only do small amounts at a time and the battery will not last if used for multiple people on a long trip.

Tablets or chemicals

For a really cheap, really light option, these work. Many avid backpackers carry these in addition to a filter in case the primary filter breaks. You simply drop one in a bottle and set a timer and forget about it.

It can take anywhere from 30 minutes to 4 hours to work. It gives off a taste that most people hate and have to use another tablet to neutralize the taste. It requires bringing lots of bottles and waiting to do a lot of water.


Buying a water filter that best suits your personal needs can transform any trip and serve as a lifeline. We hope this guides serves as a form of reference when looking for how to choose a water filter. We want you drinking clean, healthy water and wish you happy trails for your future trips.