It is necessary to filter the outdoor water while hiking?

When traveling, tap water is often not potable. In order not to spend a fortune in water bottles and avoid generating kilos of plastic waste, the best solution is to treat your water. In this file, we compare in detail the different water treatment solutions for travelers: filter gourdes, but also pressure filters, pump filters, filter straws, chemical treatments, UV lamps …It is necessary to filter the outdoor water while hiking?

Why should we treat the water when traveling?

To protect the environment

According to the American organization Centers for Disease Control and Prevention, tap water is only drinkable in rich countries: Western Europe, North America, Japan, South Korea, Australia, New Zealand… During your trip, so you will rarely be able to drink tap water.

If you buy two bottles of water a day for a year, you will therefore throw away about 700 plastic bottles during your trip. In developing countries, waste collection and recycling are not as well organized as here. So there is a good chance that these bottles end up in landfills, in nature or in the sea.

By treating your water yourself, you therefore considerably reduce your impact on the environment.

More economic

According to Numbeo, a bottle of water costs between €0.50 and €1.10 in Southeast Asia and South America. We can therefore estimate that 700 bottles of water cost around €500 over a year of travel. The water treatment systems that we are going to talk about in this file only cost between 23€ and 110€. They therefore allow you to make real savings compared to bottled water, almost equivalent to the cost of your travel insurance!

What is the risk of water without filtration?

Before choosing your water treatment system, you need to understand the risks associated with water for travelers. The water in rivers, lakes and wells can be polluted by human or animal excrement or by sewage from homes. However, except when trekking, you will mainly drink tap water during your trip. It is controlled almost everywhere in the world, but in developing countries these controls as well as the treatment and distribution facilities are sometimes deficient. If the water is contaminated, the main risk is to catch a more or less violent “tourista”: diarrhea, vomiting and stomach cramps. It may be due to the presence of dangerous micro-organisms (bacteria, etc.).


Bacteria is the first cause of diarrhea of ​​the traveler. They do not multiply directly in water, but in suspended organic matter. These are the easiest pathogens to eliminate. Bacteria are ten times larger than viruses.

● E. Coli
● Choléra
● Salmonelle
● Dysenterie
● Campylobacter
● Shigella
● Yersinia
● Aeromonas.
filtered by all the water filter system


Protozoa are often single-celled parasites that cause serious intestinal problems. When conditions become unfavorable they encyst, ceasing their movements and taking on a spherical shape. They are then more difficult to eliminate.

● Giardia
● Cryptosporidium
● Amibiase
● Douve du foie
● Echinococcose
● Vers parasites (Ténia)

Processed by: filters with pores smaller than 0.2 microns, UV lamps. Some cysts are quite resistant to chemical treatments. Thus, Micropur must be left to act for at least two hours to eliminate Giardia and Aquatabs are ineffective against Cryptosporidium.


Viruses need a living host cell to multiply
because they do not have their own metabolism. Due to their tiny size, they are very difficult to remove using a water filter. In turbid water, viruses usually attach themselves to suspended particles. It is therefore possible to eliminate them almost completely by using a filter whose pores are less than 0.015 micron. Nevertheless, to take no risks, it is recommended to purify the water after having filtered it. It is also advisable to get vaccinated against hepatitis A and against polio.

Hepatitis A

Treated by: almost completely by a filter whose pores are smaller than 0.015 micron, but in order not to take any risk, it is recommended to use a UV lamp or a chemical treatment.


According to the medical journal Prescrire, chemicals and heavy metals generally do not cause acute disorders for travelers. Adverse health effects are only to be feared in the event of prolonged exposure or significant accidental contamination (industrial accident, illegal release).


Processed by: carbon filters and charged layer membrane filters. They only filter residues of chemical pollutants and heavy metals if they are present in very small quantities and have a very short lifespan.


Tap water is usually clear, but water from rivers, lakes and wells can be cloudy. It may contain dissolved organic matter, clay particles and fine sands. Once the bacteria, viruses and parasites are treated, these particles are not dangerous, but they can give a bad taste and/or odor to the water.

Treated by: all filters, but not chemical treatments or ultraviolet lamps (the latter are also ineffective in treating bacteria, protozoa and viruses in cloudy water). Activated carbon filters remove bad taste and odors.


Be careful, water is not the only way you can catch a tourista. To limit the risks:
Eat foods that are cooked and served hot, fruits and vegetables that you have washed with treated water and peeled yourself, and pasteurized dairy products.

Avoid foods served at room temperature, raw fish and rare meat.
Avoid ice cubes, as they are usually made with tap water.

What are the solutions for filtering water?

Filtration or Purification

Water treatment solutions fall into two broad categories:

Filtration: These are mechanical systems that push water through a filter. They remove bacteria, protozoa and sometimes viruses, depending on the type of filter and pore size. They also remove particles and sometimes certain chemical pollutants and heavy metals.
Purification: It can be chemical at ultraviolet or simply by boiling the water. These systems eliminate bacteria, protozoa, and viruses, but not particles or heavy metals.

The key to choosing a water filter

The quality of the water tested

The choice of your treatment system will depend on the use you intend to make of it:

If you only plan to treat tap water which is generally clear, you will not need a system that filters particles.
If you plan to treat tap water, but also water from rivers, lakes or wells which is sometimes cloudy, you will probably need a filter to remove particles.

Virus purification

The level of risk you are willing to take will also influence your choice, especially regarding whether or not to filter viruses. During our survey, many respondents told us that they were very satisfied with filters that let through viruses, such as the Sawyer Mini or the LifeStraw Go. None told us that they had become ill while using them.

Indeed, the risk of catching a tourista because of water comes mainly from bacteria and protozoa which are eliminated by all treatment systems. However, this does not mean that it is impossible to catch a disease with a filter that lets viruses pass. If you want to be almost certain not to catch anything, choose a model that also treats viruses.


Treated water can sometimes taste bad, even if it is safe. If you want to remove this bad taste, opt for a water bottle equipped with an activated carbon filter in addition to the main filter, such as the LifeStraw Go 2-Stage, the Grayl Ultralight or the LifeSaver Liberty.

In addition to improving the taste of water, activated carbon retains much of the chlorine, pesticides and lead that may be present in the water.

However, the big disadvantage of activated carbon is that it degrades quickly. It is therefore necessary to replace the capsule regularly. For a long trip, this requires carrying a large quantity of spare capsules, which takes up space and is expensive.


No consumer water treatment solution allows you to drink sea water or urine. For this, much heavier and expensive professional filters should be used.


During our investigation, the first criticism made of filter gourds is, by far, the fact that they leak. The LifeStraw Go and Water-to-go gourds have a big problem with sealing.

As soon as they are not held straight, water will flow out of the nozzle. Also, even when they are vertical, the difference in pressure when you go up in altitude or when you take the plane pushes the water out of the gourd.

The water floods the entire contents of the backpack and risks damaging your electronic devices: camera, tablet, etc.

To avoid this problem, which seems to concern almost all water filters, the best solution is to opt for a UV lamp such as the SteriPen or a pressure filter such as the Squeez water filter.

Time of the filtration

Filtering gourds and filtering straws make it possible to obtain drinking water instantly, by sucking through a straw. However, having to vacuum to get the water through the filter can be a bit tiring after several months of travel.

With pressure filters and pump filters, you won’t need to vacuum to drink, but you will still have to put in the effort: press a flexible bag or pump.

With gravity filters, you have to find a place to hang the water bag and wait for the liquid to pass through the filter. This system is quite tedious and is especially suitable for groups or families who stay in the same place for a long time.

If you use a UV lamp, you must shake it for 48 seconds in your 50 cl bottle. So it’s not instantaneous, but quite fast and you don’t have to vacuum, which is nice over a long period of time.

Chemical tablets take much longer: 30 minutes minimum for Micropur Forte and two hours to be sure to eliminate Giardia protozoa. It’s really not practical when travelling.


Filter gourds can store water directly, eliminating the need to search for water sources during the day.

Filter straws, on the other hand, are not practical at all. You have to drink directly from the source and it is impossible to pour filtered water into a flask.

With the other treatment systems (UV lamp, pressure filter, chemical tablets and pump filter), you can store the filtered water in a classic water bottle, to be purchased separately.


When we ask travelers what they would change about their trip if they had to do it again, many answer “take a lighter bag”. To travel light, you have to pay attention to the weight of each object.

The lightest filtering systems are chemical tablets and filter straws, but very few travelers use them daily for a long period of time.

Filters equipped with a flexible bag, such as the Sawyer Mini or the Katadyn BeFree, are lighter and take up much less space in the bag than rigid filter bottles.

UV lamps are also quite lightweight and space-saving.

Service life

The service life of treatment systems is expressed in the number of litres of treatable water. Pay attention that the lifespan of the model you choose is enough to cover the entire duration of your trip.

During a one-year trip, counting two liters of water per day, you will have to treat about 700 liters. We, therefore, advise you to bring a treatment system that has a lifespan of at least 1,000 liters (or even 2,000 liters if you go with two with a single treatment system).

Water bottles equipped with a carbon filter have two lifetimes:

The life of the main filter: is usually sufficient for a long trip.

The life of the carbon filter is only about 100 liters. When the carbon filter is no longer active, the taste of the water is no longer improved and chlorine, pesticides and lead are no longer filtered. To travel a year, you have to leave with a dozen spare carbon filters.
There is no visual indicator of when the life of the main filter has been exceeded. However, the closer its end of life gets, the more difficult it becomes to suck up water. When you can no longer suck the water, you will know to change the filter. UV lamps, on the other hand, are equipped with LEDs that warn you when your lamp needs to be changed.


If for some reason you don’t feel like using a filtration system, the RefillMyBottle app allows you to find places to fill your water bottle with purified water anywhere in the world. The idea is interesting, but unfortunately the application often crashes and there are not yet many places to fill your bottle.

The best solution

According to us, the best solution is a water filter portable. It was the system that scored the highest average in our survey (9.3/10) and avoided the most purchases of water bottles

It has almost only advantages:

Small and light
No risk of flight
Even treats viruses
Fast processing
No need to vacuum, squeeze, or pump
No maintenance
No spare parts to take away
Long service life

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