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Best Water Filter and Treatment Systems for Backpacking

Best Water Filters and Treatment Systems for Backpacking



Finding water and treating it is one of the unavoidable chores that goes along with hiking in the backcountry. A fast and effective solution for this will give you more time to cover ground and keep you from catching an illness.

Depending on the water source, if you don’t treat the water there is a possibility of getting infected by bacteria, viruses, or protozoa (like giardia and cryptosporidium).

There are an overwhelming amount of water filter and treatment systems out there, so I wrote this article to help you learn about the best ones. Hopefully, you can use this information to find a system that works for you.

Continue reading to learn the top things to consider so you know how to choose the best one for you.

Just want to see my favorites? Skip ahead to the best water filter and treatment systems for backpacking.

Jason holds a Katadyn BeFree Water Filtration System

Top Things to Consider


Efficacy is the ability to produce a desired or intended result. When assessing water filter and treatment systems, it’s important to look at their efficacy. You don’t want to buy a water purifier that fails to do its job, which is to kill or remove contaminants that get you sick.

According to the CDC, boiling has 100% efficacy and is therefore the best method for water treatment. The CDC suggests bringing water to a boil for one minute to kill pathogens. If you’re at an altitude of 6,562 feet or greater, boil for 3 minutes.

Realistically, most backpackers won’t boil their water to treat it. It’s just not a practical method for someone who hikes all day. This brings us to the burning question – what’s the best water treatment method for backpacking?

The unpopular but true answer is, a combination of filtration and disinfection. As it stands, there is a slight problem with picking one method over the other. Water filters are great for removing protozoa and bacteria but they allow harmful viruses to pass through.

Alternatively, water disinfection with chemicals has 100% efficacy against everything except cryptosporidium, a nasty protozoan that can cause respiratory and GI distress.

That being said, water disinfection with chlorine dioxide (as opposed to iodine or chlorine) is almost foolproof. It has high effectiveness against cryptosporidium and very high effectiveness against everything else.

Personally, I like to use chlorine dioxide without a filter because it covers all the bases. Filtering the water first would remove the minimal chance of getting infected by cryptosporidium, but research suggests that chlorine dioxide is effective enough.

Pathogens to Watch Out For

  • Campylobacter
  • Salmonella
  • Shigella
  • E. coli
  • Enterovirus
  • Hepatitis A
  • Norovirus
  • Rotavirus
  • Giardia
  • Cryptosporidium

Further Reading


A Guide to Drinking Water Treatment and Sanitation for Backcountry & Travel Use


Efficacy of chlorine dioxide tablets on inactivation of cryptosporidium oocysts


As a general rule, it’s always best to take lightweight backpacking gear to reduce the load your body endures so you can hike happy and injury free.

There are a lot of unnecessarily heavy water filters on the market, so all of the ones I recommend in this post are light.


Anything that takes away from time on the trail is inconvenient if it’s not for fun. Things like eating, swimming, fishing, napping, and cloud watching are for fun. Pumping water is not, especially when you have a lot of miles to cover and limited daylight.

Nowadays, filtering and treating water doesn’t have to be inconvenient or time consuming. There are many convenient options and I cover them all below.

Best Water Filter and Treatment Systems

Katadyn Micropur MP1 Purification Tablets

Katadyn Micropur MP1 Purification Tablets

Weight: 1 oz treats 7.5 gallons
Active Ingredient: Chlorine dioxide

Katadyn tablets are the most effective and hassle free water treatment system I’ve used. All you have to do is add 1 tablet per liter of water and wait the recommended 4 hrs. They are effective against bacteria, viruses, and protozoa, including giardia and cryptosporidium. Unlike iodine, they don’t alter the flavor of your water.

What I like: Extremely convenient and kills ALL pathogens
What I don’t like: Possibly the most expensive form of treatment

Note: If you can’t wait 4 hours, most pathogens will be killed 30 mins after mixing, but cryptosporidium might still persist.

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Aquamira Water Treatment

Aquamira Water Treatment

Weight: 1 oz treats 30 gallons
Active Ingredient: Chlorine dioxide

Like the Katadyn tablets, Aquamira is a chlorine dioxide concoction that is effective against bacteria, viruses, and protozoa, including giardia and cryptosporidium. The only difference is Aquamira is a two part drop system so it’s a tiny bit more involved. Combine 7 drops of Part A and Part B, wait 5 min (or until yellow), then add that to 1 liter of water and wait 4 hours.

Tip: Want to learn more about Aquamira? Read my review.

What I like: Highly concentrated form of chlorine dioxide, cheaper per treated gallon than Katadyn tablets
What I don’t like: Counting and mixing the drops is a pain

Note: If you can’t wait 4 hours, use 14 drops instead of 7 and wait 45-60 min. All pathogens, including cryptosporidium will be killed.

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Sawyer Micro Squeeze

Weight: 2 oz

The Micro Squeeze is a lightweight filter that allows you to squeeze water out of a pouch (or Smartwater bottle), through the attached filter, and into your drinking bottle instead of pumping it directly from the source. Periodically, you’ll have to backwash the filter with the included plunger to unclog/clean it.

Need to filter water for a group? Read our review of Sawyer’s 1-Gallon Gravity Filtration System.

Sawyer Micro Squeeze vs. Sawyer MINI: The new Micro Squeeze has a faster flow rate than the older MINI and is less likely to clog. For that reason, I don’t see a reason to buy the MINI anymore.

What I like: Light, effective, and works for 100,000 gallons
What I don’t like: Not effective against viruses, requires unclogging

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Katadyn BeFree Filtration System 1L

Weight: 2 oz

The BeFree is a collapsible water reservoir with a screw top nozzle that has a built in filter. Its flow rate is faster than a Sawyer, but it’s not as easy to unclog/clean it so you’ll likely have to replace the cartridge down the road.

You can drink directly from the BeFree, but most prefer to squeeze the water into another bottle they can chug from.

Katadyn also makes a version of the BeFree that holds 3 liters. It features a handle so you can hang it and use gravity to filter instead of the squeeze method.. Read our review of the Katadyn BeFree 3L.

What I like: Faster flow rate than Sawyer filters
What I don’t like: Not effective against viruses, clogs, doesn’t screw on to other bottles

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MSR Guardian Purifier

Weight: 1 lb 1 oz
Best For: Canyoneering

If you’re headed to Utah’s Canyon Country where the water is full of sediment or traveling to a developing nation, then you need something more robust than a dinky filter and purification tablets.

Enter the Guardian Purifier, a military grade, self-cleaning workhorse that is built to withstand the harshest conditions. Unlike any other filter, it not only removes bacteria and protozoa but also purifies viruses without the use of chemicals.

What I like: Self cleaning, high flow rate, will not clog, the only filter that kills viruses
What I don’t like: Relatively heavy, expensive

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Systems I Don’t Like and Why

SteriPEN Ultra

Although this UV light pen is lightweight and treats water fast, it requires a USB battery charge to work. Between my smartphone and camera, I already have enough rechargeable items in the field to be adding another.


These purification tablets are made by MSR, and while convenient, they’re not effective against cryptosporidium.

Potable Aqua

Potable Aqua purification tablets are carried by most outdoor retailers, but they contain iodine which has a bad aftertaste. Potable Aqua sells a version with a neutralizer that removes the aftertaste, but neither product is effective against cryptosporidium.

Gravity Filters

Gravity filters require that you find a spot where you can position two bags of water so one is higher than the other. The higher bag drains into the lower bag through a filter.

The Platypus GravityWorks has a large capacity at 4 L, and could come in handy with a large group. It uses passive filtration and doesn’t require any pumping or squeezing.

Sawyer also makes a 1-gallon gravity filtration system (read our review), and Katadyn has a 3 L system (read our review) worth looking into.

That said, I like to hike all day and limit the amount of water I carry. I’d rather fill up more often than hang a bag twice a day and haul all that water around.


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