Field Filter. Part - 1

How to Choose a Hiking Filter.

When hiking, you often have to drink water from unclear rivers and streams. Sometimes the water looks clean, but there are cows grazing upstream. Other times, you have to set up camp where the only water source is a stagnant pond, and the water is murky with an unpleasant odor. In the past, hikers had to rely solely on coarse water filtration, boiling, and their own immunity in such situations, while also suppressing their disgust. But today, water can be purified and even disinfected in the field using compact microfilters. Here, we will discuss the different types available and how to choose the right one.

When is a hiking filter useful?

Tourism

On many hiking trails, it is impossible to buy bottled water or replenish supplies from a reliable source—such as a mountain stream or an artesian well—in a timely manner. The water on the trail can be murky due to silt and sand, tea-colored from decomposing plant matter, or seemingly clean but contaminated with dangerous pathogens due to animal or human activity. For instance, many streams are undrinkable during floods: the water carries masses of silt, soil, sand, and debris from eroded banks. And during treks in Nepal, even seemingly clean high-altitude lakes and streams are unsafe to drink from, as they can lead to gastrointestinal infections.

In hiking trips, a filter allows you to utilize previously unreliable water sources and save fuel for boiling.

A hiking filter purifies water from mechanical impurities and dangerous microorganisms. This means you significantly reduce the risk of unpleasant issues like feeling unwell, diarrhea, and the presence of parasites in your body. With a filter, you can boil water much less frequently on hikes, saving time and reducing fuel consumption, which makes your backpack lighter. You can also avoid carrying extra drinking water on days when reliable water sources are not expected along the route—you can simply filter the necessary amount on the go.

Traveling in regions with poor water supply

In many regions of the world, local water supply systems do not meet sanitary standards: water is not properly treated, becomes contaminated due to worn-out pipes, and sometimes even mixes with sewage. Drinking tap water in such places is dangerous. An example is Nepal: the local water supply leaves much to be desired, and only boiled or bottled water is safe to drink.

However, boiling water and buying drinking water costs money, and the higher the mountain lodge, the higher the prices. For example, in Namche Bazaar, a liter of water costs 100 rupees, while in Gorak Shep, it costs 400 rupees. Here, a hiking filter can save you a lot of time and money on clean water and fuel for boiling.

In some regions, the water does not meet sanitary standards. A filter helps avoid poisoning and saves money on bottled water.

Emergency situations

In conditions of flooding or earthquakes, water supply systems can be disrupted. In such cases, the water requires very thorough purification, as it is saturated with various infections, parasites, and contaminants.

A hiking filter can be one of the steps for purifying and disinfecting drinking water.

When the local water supply system is damaged due to an emergency, the water coming from the tap can be purified using a hiking microfilter.

What makes a hiking filter effective

Essentially, a filter consists of a replaceable cartridge with a filtering substance inside. This can be ceramic, hollow fibers, quartz, fiberglass, or even cellulose. However, the most important factor is the pore size in the filtering substance. It should be no larger than 0.2 microns. This size was chosen and established as an industry standard for a reason. Through such small pores, not only the tiniest mechanical impurities like sand cannot pass, but also most of the common dangerous bacteria, parasites, and unicellular microorganisms found in water. These are often the cause of gastrointestinal disorders. Filters with pores no larger than 0.2 microns are referred to in the industry as microfilters.

Miscellaneous