Photo by Natalie McMillan

Read something else

We Sawed a Sawyer Squeeze Water Filter in Half!

Have you ever wondered how a Sawyer Squeeze water filter works? We cut one open to to give you an INSIDE LOOK.

Atlas Guides Team       Tech on the Trail       10/15/2019

Atlas Guides Team

Tech on the Trail

10/15/2019

The Sawyer Squeeze water filter is the most popular filter used by long-distance backpackers due to its ease of use and lightweight quality.

We wanted to get an INSIDE look at the Sawyer Squeeze to see how it really works, so we cut one open and took a close look with a microscope.

 

Read our series of Sawyer filter reviews:

Review: the new Sawyer Micro Squeeze

Sawyer Squeeze and Micro Squeeze Flow Rate Tests

Should I Carry the Sawyer Syringe?

Guthook filtering water into a bottle using the Sawyer water filter.

Guthook filtering water into his water bottle using the Sawyer Squeeze.

Here is what we did...

Guthook filling his Sawyer bag with dirty water.

We filled the Sawyer filter bag with some murky pond water.

Guthook filtering water into his bottle using a Sawyer water filter.

Then we forced pond water through the Sawyer Squeeze into a water bottle.

A woman backflushing the Sawyer Water Filter.

Next we backflushed the Sawyer Squeeze with clean water.

We disassembled the filter

A person drilling into a Sawyer Water Filter.

We drilled out the locking points on the side of the filter.

A look inside a Sawyer water filter.

Here is a view of the water intake side of the filter.  This is the side that the dirty water flows into.

A Sawyer water filter separated into three pieces.

Then we unscrewed the filter and removed the internal filter.

A look inside a Sawyer water filter.

And here is a view of the outflow side of the filter.  This is where the clean water flows out of the filter.

Microscopic View

A woman analyzing a Sawyer water filter with a microscope.

We bought an inexpensive microscope and hooked it up to a laptop to get a close up view of the filter.

Looking inside a Sawyer water filter through a microscope.

Focusing the microscope on the outflow end of the filter.

A Sawyer water filter through a microscope.

The microscope reveals the small outflow tubes, where the clean water comes out.  A solid resin keeps water from flowing around the tubes.

Looking inside a Sawyer water filter through a microscope.

Here, we set up a microscopic view of the long filter loops where the water flows into the filter.  Notice some dark particulate matter stuck to the sides of the loops.  Backflushing the filter removes these contaminants.

Final disassembly: saw in half!

To get a closer look at the long filter loops we removed the plastic housing that protects the filter from being damaged.

A man cutting open a Sawyer water filter.
Looking inside a Sawyer water filter through a microscope.

Now you can see the long filter loops (some tubes were damaged during the disassembly process).  Each long filter loop is secured to the outtake section of the filter, which is the portion covered by protective tissue in the photo.

Looking inside a Sawyer water filter through a microscope.

The microscope reveals contaminants stuck to the side of the long filter loops.

Looking inside a Sawyer water filter through a microscope.

Contaminated water comes into contact with the outside of the long, looped filter tubes. The pores on the side of the tubes are so tiny (0.1 microns or 0.0001 millimeters), that bacteria (0.2 microns to about 3 microns) and Giardia (7 to about 10 microns) can’t pass through the filter.  Water enters the wall of a tube through these small pores and comes out the end of the tube as purified water. Bacteria, Giardia, and debris are simply too big to pass through the pores. As the pores get clogged with debris and contaminants, the flow rate of the filter decreases.  To increase the flow rate of your filter, backflush the filter to remove the debris and contaminants.


Want to keep up with all that’s going on at Atlas Guides? Sign up for our newsletter!

Read more!

Check out more posts by Paul Bodnar!

Download our popular hiking and biking guides!

Trail guides that get you to places you’ve dreamed of.

As the makers of Guthook Guides, Bikepacking Guides, and Cyclewayz, we help you navigate the most popular trails around the world on your smartphone. Our hiking guides and biking guides work completely offline. Let Guthook guide your next adventure!

Showers Lake Vista, Tahoe Rim Trail
Photo courtesy of the Tahoe Rim Trail Association

A lake reflects a nearby wildflower meadow and trees.

Showers Lake Vista, Tahoe Rim Trail
Photo courtesy of the Tahoe Rim Trail Association

Trail guides that get you to places you’ve dreamed of.

As the makers of Guthook Guides, Bikepacking Guides, and Cyclewayz, we help you navigate the most popular trails around the world on your smartphone. Our hiking guides and biking guides work completely offline. Let Guthook guide your next adventure!

Download our popular hiking and biking guides!

About the Author

A man wearing an Arizona Trail baseball cap stands in a field in front of a mountain.

Paul Bodnar

Paul has always liked hiking and thru-hiked the Pacific Crest Trail in 1997 after college. After years of working in chemistry, he wanted to create a career involving the outdoors, so he hiked the Pacific Crest Trail again in 2010 to do research for his guide book Pocket PCT. He realized that creating a smartphone app for navigating the outdoors would make it easier to keep the data current and provide a better way to navigate. While hiking with Ryan (aka Guthook) in 2010, they decided to work together to create the first comprehensive smartphone guide for the Pacific Crest Trail. Now with the help of a team of great people they have created over 50 guides for trails around the world.