Choosing a Water Filtration System

Working as a hiking guide I get lots of questions about water safety.  Frequently when I talk with clients on a hike regarding the spring water in the Smokies, where I work, people will inquire whether or not the water is safe enough to drink.  This is where my hiking guide hat goes on and I let people know with all water it is strongly encouraged to filter out contaminates or to treat it with a chemical drop/tablet.  With all the changes to gear on the market lately, I thought it would be helpful for newbie hikers to compare water filtration methods to help you decide which method is right for you. 

No Filter, No Problem

But this article is all about filters, right?!  Well, we can't talk about water filters without talking about the fact that some people just don't filter water.  And that's ok!  The no filter method was the most popular method I saw when thru hiking the Appalachian Trail in 2012.  In fact, I know many, MANY thru hikers who didn't treat their water after miles of hiking back then.  By not filtering your water, however, you are opening yourself up to contamination issues, Giardia being the most common here on the east coast.  With many, many options on the market, I highly recommend looking into some of the lighter weight filters or treatments on the market today. 

Aquamira Drops

Aquamira Drops were my go-to method of filtration back in the mid 2000's.  In fact, it's the first method of filtration I ever used.  With this method, all you'll need to do is mix together Part A and Part B in the provided cup, wait for it to activate, and add it to your water.  The upside of this is that these drops are pretty cheap in the world of water filtration.  They're also incredibly lightweight.  However, in my experience, Part A and Part B never seem to run out at the same time despite using the exact same amount of each drop.  You'll also be waiting 15 to 30 minutes for your drinking water after the drops have been added.  Another downside? Unless you're pre-filtering your water, you might find yourself drinking a little bit of sand at the bottom.  These drops, when they've sat too long in your hydration bladder or bottle, can also taste strongly of chlorine.  

Iodine Tablets/Drops

Ahhh, good old Iodine.  In tablet form or in tincture form, this stuff is great to carry in your pack.  On my guided trips I carry iodine solution in my first aid kit for disinfecting wounds and kitchen utensils.  In a pinch, I could use it to treat my water too.  Of course, the downside to iodine solution/tablets is the same as it is for Aquamira - waiting to drink water and also possibly drinking up some sand or dirt.  Unlike Aquamira, however, iodine doesn't taste like chorine.  It tastes like iodine - and it tastes like iodine all the time.  

Bleach Drops

Yes, I said bleach drops.  Believe it or not, the stuff you use to get your whites clean in the laundry can also be used to purify your water.  A few drops will do the trick.  Carrying a small dropper of bleach can be an extremely cheap, lightweight solution to keeping your water clean.  However, carrying bleach often means you've repackaged it.  Making sure you've got the bottle sealed up tight is crucial in your pack.  Spilling bleach on gear is never fun!  Like Aquamira and iodine, drinking sandy water is also a possibility.  Again, water that sat in your hydration bladder or bottle too long will also possibly have a chlorine aftertaste.  


There are many brands of water filter pumps out on the market right now.  NoKey has formerly owned an MSR Sweetwater Pump and the gear shop I worked at in Maine also carried Katadyn Micro filters.  Years ago, these filters were your best defense against not only bacteria, but also protozoa.  However, these days these filters can definitely have a few downsides.  First of all, these filters are pretty heavy, weighing in at a pound or more sometimes.  There are quite a few parts to keep track of, which can make cleaning difficult.  Also, the filters have what we would now consider to be an extremely short shelf life, sometimes as low as 750 liters of water.  Many hikers now find it cumbersome to have to find water deep enough to float your filter, pump your water, and hold your bottles.  However, on the plus side, your water won't have that funky flavor chemical drops tend to leave in the bottle!

Sawyer Mini/Squeeze

The first time I saw a Sawyer filter was in 2012 and I only knew three people using one.  In 2013, it was damn near the only filter I saw on the trail.  This tiny filter has a life of 100,000 liters and weighs approximately 2 ounces (the Mini, not the Squeeze).  It's a lightweight filter that I personally put right on the end of my Camelbak hose and drink right out of, eliminating the need to squeeze water altogether.  The downside of this filter is the fact that many people find the collapsable bottles that come with the filter to be cheap and low-quality.  It also does need to be back flushed regularly to keep it running at a decent speed.  Many people think these filters are too slow.  


This UV pen took the market by storm several years ago when they were first released.  Using UV light to treat water seemed like something straight out of science fiction.  By removing viruses, bacteria, and protozoa, this thing seemed to be the perfect water filtration solution.  The fact that it doesn't use chemicals to treat the water and, frankly, it looks cool, are big selling points to hikers.  The downside to this pen is the thing that makes it neat - it's electronic.  Taking electronics out into the backcountry can sometimes be disastrous.  The SteriPen needs batteries and I've seen these pens fail many times when it comes treating water.  While they're quick to use (1 minute for 1 liter of water) like other methods, you may want to pre filter water to avoid getting sand or debris in your bottle. 

Boiling Your Water

Of course, the tried and true method of boiling water to sterilize it never goes out of fashion.  Of course, if you don't carry a camp stove or maybe if it's been raining for a few days and you can't dry out any wood to build a fire, this can be a problem.  Also, this method will take a little while. Building the fire, boiling the water, and then letting it cool down to a drinkable temperature can take upwards of 20 minutes.  

Here are just a few of the most common methods of treating water in the backcountry.  What water filter method do you use?  What do you like and dislike about your preferred method?