Water Filtration and Treatment for Fastpacking

Clean water is something we often take for granted, but in the backcountry it is an important factor of staying safe and healthy during the adventures we take. Finding the right method to treat your water while fastpacking will make your trip better and your experience more enjoyable. Fastpacking presents its own unique requirements for purifying water. Because speed and weight are of top priority when fastpacking there are only a few options that we recommend while on the trail.

Types of Water Treatment

There are three main methods for treating water in the backcountry while you are fastpacking. Filtering, UV treatment, and chemical treatments can all be used to make your drinking water more safe to drink. Each method has its benefits and detriments, but we have narrowed each category to help your decision to find what it right for what you are doing.

Sawyer Mini Water Filter

The Sawyer Mini Water Filter is our top pick for water treatment while fastpacking. It offers an easy to use solution in a light package while still protecting against 99.9999% of all protozoa and bacteria. The main cartridge weighs 2 ounces and is rated to filter 100,000 gallons of water.


  • Low cost
  • Lightweight
  • Easy to use
  • Protects against 99.9999% of all protozoa and bacteria


  • The included pouch is hard to fill in low flow streams. However the main cartridge can be threaded onto other, hard sided bottles.
  • The filter does require you to back flush it after use with the included syringe
  • The pouches can be broken if they are squeezed too hard

UV Steri Pens

Treating your water via UV light is one of the most effective and fastest methods for treating you against almost all waterborne protozoa, bacteria, and viruses. It is a recommended method by the US EPA. Steri Pens have been on the market for about 10 years and have quickly become a popular choice for many backpackers. The lightest models weight less than 5 ounces, and can purify up to 50Ls of water on what set of batteries or charge. However, because they require batteries it is important to make sure you have adequate capacity before heading out. Cold temperatures can also affect battery performance causing unexpected outages.


  • Fast acting and easy to use
  • Protects against protozoa, bacteria, and viruses
  • No field cleaning
  • Treats viruses and is recommended for international travel


  • Cost
  • Battery powered
  • Heavier than the lightest options
  • Temperatures can affect the battery capacity
  • Does not work well with cloudy or murky water

Iodine and Chlorine treatments

Chemical water treatments are a great backup solution incase your filter fails. They are lightweight, inexpensive, and effective against most waterborne threats. Chemical treatments are ineffective against Cryptosporidium so it is not recommended to rely solely on chemical treatments.


  • Cheap
  • Lightweight
  • Great backup incase filter or other purification method fails


  • Do not treat against cryptosporidium in a reasonable amount of time
  • Have a limited shelf life with expiration date
  • Taste can discourage use
2018-04-30T01:01:26+00:00 Categories: Fastpacking, Gear|Tags: , |0 Comments

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