Water Treatment for Hikers, Vol. 2 – Water Treatment Methods

Water Treatment for Hikers, Vol. 2 – Water Treatment Methods

When I was a kid, I ran all over the mountains and foothills of the Mid-Atlantic drinking water out of streams and other running bodies of water. When I got in the military and got into the medical field, I REALLY learned about the importance proper hydration and water treatment. In the military, the most common method of treating water is water purification tablets (Iodine) or Aquamira.


In this episode, I am going to talk about the different popular methods of water treatment and try to hit their pros and cons. I will also try to give some examples of each where applicable.


Pump Water Filter/Purifier – A mechanical filter works by pumping water through microscopic pores in some sort of filter element. The downside to mechanical filtration is that the filter is going to get clogged up, requiring you to clean out the system and eventually replace it. Mechanical Water Purifiers work in a similar fashion to filters, but can remove Viruses.


  • You can get water from pretty much any source
  • You can get your water quickly
  • You can replace the filter element
  • You get exactly as much as you need


  • Heavier than most of the other options
  • You must clean the filter
  • You must pump the filter
  • Price

MSR Guardian – MSR’s flagship, it pumps up to 2.5 liters per minute and 10% of every pump stroke serves to backflush the filter, saving you from having to clean it like other filters. This purifier filters particles down to 0.02 microns… small enough to filter out viruses. The filter cartridge is rated for 10k liters and is replaceable.  $350

Katadyn Pocket Water Filter – Katadyn’s flagship, it is effective only against bacteria and protozoa due to it having a pore size of 0.2 microns.  Good for 1 liter per minute, the filter cartridge has a life of 13K liters . $240


Gravity Filter – Gravity filters work like pump filters. The difference is they work via…. you guessed it, gravity. You place dirty water in a dedicated dirty container and then let it flow down via gravity to a clean container.


  • Easy to replace cartridges
  • Good for a large group
  • You don’t have to do much, just let gravity do the work


  • Slow
  • Requires you to clean the filter frequently
  • Hard to get water out of shallow sources

MSR Autoflow/Platypus GravityWorks – Similar offerings from two different companies, both are easy to use to filter large quantities of water. About $100. MSR Autoflow


Squeeze Filter – Squeeze filters work similar to gravity filters but instead of waiting for gravity, you force the water through the filter cartridge by squeezing water from a dirty “source” bag/bottle to a “clean” reservoir.


  • Inexpensive
  • Easy way to quickly filter a small amount of water
  • Small and light


  • Frequent backflushing is generally required
  • Can only filter in small amounts generally due to reservoir size

Sawyer Squeeze/Sawyer Mini – both are very popular among hikers. Easy to use, pain in the butt to have to regularly backflush, they are a readily available, inexpensive option. $20-$40 Squeeze Mini

MSR Trailshot – MSR’s answer to the Sawyer Squeeze, this is a nice little filter. Weighing in at only 5 oz, it fits in a pocket and efficiently filters one liter per minute. $50

Chemical Treatment – Effective against bacteria, protozoa and viruses, chemical water treatment is a cheap and easy to use option. Mostly chlorine or Iodine based, they usually come in pill or drop form.


  • Easy to use
  • Cheap
  • Ultra-light weight


  • VERY slow. Usually you have to wait 30 minutes or longer for them to work
  • Can leave a chemical taste
  • Can be some concerns with different medical conditions
  • As we mentioned in Vol. 1, not as effective vs Cryptosporidium, you MUST use the proper amount and wait the proper time or it is useless.

Aquamira – a binary system, you mix part A and part B then add to water. No taste. Works well on Cryptosporidium. Kit treats up to 30 gallons. $15

Potable Aqua – Iodine based tablets. Awful aftertaste. Not good vs Cryptosporidium. $7, plus $5 for the taste neutralizer tablets.

MSR Sweetwater Solution – For use with the Sweetwater Pump Filter, this adds virus protection to a popular MSR filter. $15 for up to 80 gallons.

UV Treatment – Stick your little battery-operated wand in a bottle of water, press and hold the button and 60 seconds later you have drinkable(ish) water. Effective against bacteria, protozoa and viruses.


  • Ease of use
  • No cleaning required


  • Doesn’t work as well in water that is cloudy or silty
  • Batteries necessary
  • One bottle at a time
  • After treatment, cloudy water is still cloudy water, just drinkable now.

SteriPen– able to purify about 50 liters per set of 2AA alkaline batteries. Prices range from $60-$100 depending on model.


Boiling – You gather some water and bring it to a boil for at least 1 minute, longer at altitude.


  • Easy to do
  • Very cheap
  • Cloudy water still boils


  • Water needs to cool down
  • Water must boil
  • Fuel is required
  • If open flames are banned, you are screwed.



Tips :

  • Because more people and livestock live at lower elevations, water at higher elevations is generally cleaner
  • That cattle stock pond over there? Don’t drink from it unless you must, and if you do, treat for viruses
  • Avoid stagnant ponds in heavily logged area. Heavy metal run off is a real thing.
  • Use LNT principles and do not camp, use the bathroom or clean dishes within 200ft of water sources
  • Seek out clean running water over stagnant murky water
  • Follow all product directions. If you don’t you might just be wasting time and inviting disaster.
  • Source clean water activities upstream of dirt water activities
  • After a heavy rain, wait a short while before gathering water from a ground source. Water washing over surface areas stirs up mud and increase bacterial load.
  • Use a prefilter if you have one, or make one with a bandana
  • Get water from the surface, sediment and other gunk sinks
  • Wash your hands
  • Keep dirty water and clean water separate


Water Treatment for Hikers, Vol. 1 – Why we treat our water


  1. Avatar


    Good article series!

    I plan to provide a “tree prize” solution for the Texas Fairfield Group Hang that I’m working on to solve help with the difficulty in extracting water for filtering from shallow areas. Sort of a redneck version of the MSR trailshot. Stay tuned…

    Take it easy,

  2. Avatar


    Here is a picture of our red-neck gravity systems las week in the BWCA. All in, about $30 each.https://uploads.tapatalk-cdn.com/20170916/9f77b6dbe3ed411027d897b0166027bd.jpg

    Two plastic 5L bags, a little hose and a sawyer squeeze

    Sent from my iPhone using Tapatalk

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