How to Choose the Right Hiking Water Filter
Can you survive in the backcountry without a hiking water filter? Yes.
Is it possible to survive a car crash without airbags and a seat belt? Yes.
Both are possible, but why take a chance with your life or your health?
Backcountry waters, as clear and pristine as they may appear, can carry a whole arsenal of microscopic pathogens ready to wreak havoc on your stomach.
Some of these tiny buggers include bacteria, protozoa, and viruses, that all thrive in water. Backcountry water doesn’t need to appear dirty to be bad for you, so don’t be fooled by a crystal clear stream.
Photo courtesy of Brian Drum
If you drink from a water source without using a hiking water filter, and ingest some of these microbial pests, you can face vomiting, diarrhea, cramps, fatigue, and nausea for several weeks!
If you’ve ever had a gastro-intestinal illness like food poisoning or worse, you know it is something you don’t ever want to repeat. Don’t take the risk with your health. Use a hiking water filter.
Treat it Before You Drink It! The Different Ways to Treat Water from Natural Sources
In the backcountry, there are a number of methods for treating water to make it potable:
Before the invention of hiking water filters, there was boiling. Of course, it is just as reliable today as it was then.
You know the drill: Throw water in a pot, heat it up, wait, let it boil for a while, then wait again for the water to cool down.
Examples: Jetboil / MSR Pocket Rocket / any other stove and pot system
Advantages: Boiling water kills all the buggers you need to worry about very effectively.
Disadvantages: Boiling alone does not clean up the other junk like sediment, sand, or plant debris. For that, you need a filter of some sort. One method is to let the water sit in a bucket for about an hour so that all the sediment will sink to the bottom.
Boiling also requires extra bulky gear and fuel. You may already have this for your cooking needs, but if not, that’s a lot of extra gear.
Boiling takes time. Expect to wait about twenty minutes for the whole process.
2. Pump Filters and Purifiers
Advantages: In one small pump-action hiking water filter unit, you can make potable water almost instantly. Just find a water source, pump, and drink up!
Examples: MSR HyperFlow / Katadyn Pocket Water Filter / Katadyn Hiker Pro / MSR SweetWater / First Need XL / Katadyn Vario
Disadvantages: Depending on the model, the pumping might take a lot of effort. Also, pump filters have a lot of parts, and you will probably have to replace the filter element eventually.
These hiking water filters require routine cleaning. It’s ideal if your model is “field cleanable.” To improve the longevity of your filter you should pre-filter your water to first get out all the grit and dirt. You can use the bucket method above, or strain water through a bandana or coffee filter.
Note that water filters remove dirt, bacteria, and protozoa, but do not take care of viruses. In the U.S. and Canada, backcountry waters are usually considered free of viruses.
But if you are traveling internationally, or just to be on the safe side, you should invest in a pump purifier, which is a pump filter with an additional purifying element that stops viruses dead in their tracks.
3. Gravity Filters and Purifiers
Gravity filters and purifiers have the same type of filtering element as the pump models, but instead you let gravity do all the work for you. Just set up the filter with water, and wait for it to drip through the filter.
Examples: Katadyn Gravidyn / MSR AutoFlow / Platypus CleanStream / Sawyer Complete Water Treatment System
Advantages: This method takes little effort and filters or purifies just as effectively as the pump version.
Disadvantages: As you can imagine, letting gravity do its thing takes more time. This is a great method though, for filtering large quantities of water overnight at base camp, or if time is not a great concern.
4. Squeeze Bottles
Squeeze bottles are basically a plastic water bottle that filter out microbes before going through a straw or mouth piece. They are also called “in-line filters”. Water is forced through the filter when you squeeze the bottle, or through the suction of drinking from a straw.
Examples: Katadyn MyBottle (Water Filter and Water Purifier Versions) / Sawyer Four Way Water Filter System
Advantages: Squeeze Bottle filters are more natural to use, since you drink from them as you would an ordinary sports water bottle.
Since there is no pump, there are fewer parts and less bulk. Cost: squeeze bottles are generally the least expensive hiking water filters.
Disadvantages: Squeeze bottles may disappoint if you are really thirsty. The filter of course slows the flow of water and you will be doing a lot of squeezing until you get a decent amount of drinkable water.
(On the other hand, pump-action hiking water filters improve the flow, and a few will literally gush water out.)
A Note on Filters:When looking for hiking water filters, whether the pump, gravity, or squeeze bottle type, make sure that you choose one with the right pore size. What’s Pore Size? Pores are the tiny holes that allow water to pass through the filter.
If the holes are too big, the tiny pests can get through. To avoid this, choose a filter pore size of 0.2 microns, and make sure that this is the “absolute” pore size and not the nominal size. That means that the largest holes are no bigger than 0.2 microns, and will block out everything except viruses (for that you need a purifier).
5. UV Light Pens
Welcome to high-tech water purification. Insert the UV pen or wand in the water, press a button and just like magic, the UV light zaps all of the dangerous microbes, including viruses.
Advantages: UV light pens are lightweight, super easy to use, and effective at purifying water. No complicated parts or filters to clean. They can fit in a pocket and are great for the backcountry or traveling.
Disadvantages: UV pens won’t filter out any gunk that might be in the water, and if the water is dirty with sediment or mud, the UV light isn’t effective. Hopefully, you can find fairly clear water.
SteriPEN also makes an inexpensive pre-filter which attaches to standard water bottles. This extra piece of gear solves the dirt problem very well.
In order to pre-filter out sediment, you can also try the bucket method mentioned above, or use a coffee filter. (Some people have even recommended using a bandana to filter water, but I think the holes in the fabric are too big to be very effective.)
UV light pens also need electricity, so your water purification will depend on your stock of batteries.
6. Oxidant Solution Pen
Similar in size and format to UV light pens, Oxidant Solution Pens use salt and an electrical charge to purify water and kill any microbes.
Examples: MSR MIOX
Advantages: Oxidant solution pens effectively purify water in a light package, and are just as easy to use as UV pens. Like UV light pens, there is no complicated assembly, maintenance or cleaning. Just add salt (once in a while) and pop in batteries and your water is good to go.
Disadvantages: This pen, itself, doesn’t filter out sediment. So if you value crystal clear drinking water, use one of the methods described above. The pen needs salt and batteries to work, so you’ll need to pack extra just in case.
Some people note that the oxidant solution affects the taste of water slightly (probably because of the salt). If that is a big issue for you, look at another filter or purifier option.
7. Chemical Tablets
Even if you have another filtering or purifying method in your pack, consider it a must to take chemical tablets. Tablets are so small that you won’t feel the weight and they just might be the emergency backup you need in the backcountry.
Examples: Chlorine Dioxide / Iodine
Advantages: Chemical tablets are lightweight, compact, and effective at purifying water. Due to the small size, they should be carried always, even if you have another filtering or purifying method.
Disadvantages: Probably the biggest drawback to chemical tablets is the effect on the taste of water. As you can imagine, the tablets leave the water with a slight chemical taste.
(If you live in certain urban areas, though, you may well be used to that taste in your tap water! So, no big deal for you.)
Also, iodine does not kill the protozoa, Cryptosporidium. While chlorine dioxide does kill that microbe, the tablets need a few hours to work before you can drink.
Like other purifier-only methods, tablets do not clean the dirt out of water. If the water is full of sediment, let it settle first, skim the clear water off the top of your bucket, or pre-filter the water.
More Hiking Water Filter Tips
When choosing a hiking water filter or another water treatment system, remember these points:
1. Avoid getting your water near heavily populated areas or near large agricultural areas. The chemical pollutants and runoff that can get into water may be unfazed by water filters or purifiers.
2. Travel with medication. Plan B: in the event you get sick, at least you’ll have the tools to get better quicker. If you’re traveling to areas with known water-borne illnesses, consult with your doctor and get a prescription for the necessary medication to combat those illnesses.
3. Maintain hygiene when filtering your water. Be careful about touching water that can be potentially contaminated. You can easily transfer microbes to your mouth, or to the clean parts of the hiking water filter you are using, like mouthpieces or straws.
4. Take a small collapsible bucket or dipper in order to gather water from the source. That way, you keep the potentially contaminated water in a separate container away from your filter, and you can also let any dirt and silt settle to the bottom.
The Bottom Line
If you are hiking in the backcountry, away from running, treated water, always carry some method of treating water.
For any hike, chemical tablets should be included in your emergency pack of survival gear or first aid kit. Water is essential for survival and humans can’t live very long without it.
For backpacking, a hiking water filter will make it easy to get reliable drinking water on long treks, without toting several liters of water.
Don’t assume you’ll be able to find water. Check in advance to make sure that your destination has natural water sources. Remember that rivers, lakes, and creeks can all go dry in some seasons.