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MSR AutoFlow XL Review

Our favorite for large groups and base camps.
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Price:  $100 List | $74.96 at Backcountry
Compare prices at 3 resellers
Pros:  Durable, easy to use, efficient, high volume
Cons:  Requires regular maintenance, flow rate is sub-par, filter can't be frozen
Manufacturer:   MSR
By Amber King ⋅ Senior Review Editor  ⋅  Oct 16, 2019
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63
OVERALL
SCORE


RANKED
#17 of 20
  • Water Quality - 20% 8
  • Durability & Maintenance - 20% 6
  • Treatment Time - 15% 4
  • Weight & Packability - 15% 4
  • Ease of Set-Up - 15% 6
  • Ease of Filtration - 15% 9

Our Verdict

Do you need clean water for large groups of people? The MSR AutoFlow XL gravity filter stands out for its large capacity reservoir that filters 10-liters of water with minimal effort. The gravity filtration set-up requires you to collect water, hang the bladder, and wait. We tested this while guiding a large group of 20 students along the Gunnison River in clear and turbid water conditions. In both cases, this filtration system gave us the water we needed. While our most significant caveat is the amount of backflushing required to maintain a reasonable flow rate, we appreciate its relatively fast flow rate and packability. This is our favorite model for clean water at base camp or when traveling in groups.


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Price $74.96 at Backcountry
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Pros Durable, easy to use, efficient, high volumeFast, easy, hands-free filtration, large volume, storageEasy to use, fast flow rate, collapsible, lightweightLightweight, adaptable, easy to use, lifetime guaranteeLightweight, great price, durable design, fast flow, high volume filtration
Cons Requires regular maintenance, flow rate is sub-par, filter can't be frozenA little expensive, can't gather from shallow sources, clogs with heavy sedimentLacks durability and reliabilityNot great for group use, better if you replace the bagsDoesn't filter out viruses, no additional storage reservoir
Bottom Line Our favorite for large groups and base camps.A fast and easy to use gravity filter perfect for dynamic duos, solo travelers, and groups.Our favorite lightweight on-the-go filtration system.Simple filtration that is light and reliable with a lifetime guarantee.The best value gravity filter on the market.
Rating Categories MSR AutoFlow XL Platypus GravityWorks Katadyn BeFree Sawyer Squeeze Katadyn Gravity Camp 6L
Water Quality (20%)
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8
10
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8
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8
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8
Durability & Maintenance (20%)
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6
Treatment Time (15%)
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9
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9
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8
Weight & Packability (15%)
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Ease Of Set Up (15%)
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Ease Of Filtration (15%)
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9
Specs MSR AutoFlow XL Platypus... Katadyn BeFree Sawyer Squeeze Katadyn Gravity...
Type of Filter Gravity filter Gravity filter Squeeze & on-the-go Squeeze, in-line, on-the-go Gravity filter
Time to Treat One Liter (Timed Test) 2 minutes 52 seconds immediate 40 seconds 64 seconds
Measured Weight (entire kit -- oz) 16.2 oz 11.5 oz 2.1 oz 5.7 oz 11.7 oz
Storage Capacity 10L 4L 0.6 L Varies 6L
Removes Bacteria? Yes Yes Yes Yes Yes
Removes Protozoa? (Cryptosporidium, Giardia Yes Yes Yes Yes Yes
Removes Viruses'? No No No No No
Removes Chemicals? No No No No No
Removes Heavy Metals? No No No No No
Removes Particulates (sediment, microplastics)? Yes Yes Yes Yes Yes
Filter Pore Size 0.2 microns 0.2 microns 0.1 micron 0.1 micron 0.2 microns
Advertised Flow Rate 1.74L/min 1.75L/min 2.11 liters per min 1.7L/min 2 L/min
Dimensions 11 x 7 x 3 in 9.4 x 3 in 9.05 in x 2.73 in 11 x 6 10 x 6 x 2.4 in
Filter Media or Active Ingredient Hollow Fiber Hollow fiber Hollow Fiber Hollow Fiber Pleated glassfiber
# of liters/galloons per lifetime 1500 liters 1,500 liters/396 gallons 1000 liters/264 gallons 378,541 liters/100,000 gallons 1,500 liters/396 gallons
Water Bottle Adapter Yes No Yes No No

Our Analysis and Test Results

The AutoFlow XL gravity filtration system requires no hands-on work to filter 10L of water in one sitting. It's our favorite for basecamps, large groups, and whenever large quantities of water need to be filtered.

Performance Comparison


The 10L MSR Autoflow system is a perfect way to cater to large groups or basecamp.
The 10L MSR Autoflow system is a perfect way to cater to large groups or basecamp.

Water Quality


The AutoFlow XL is capable of removing all the critical biotic and particulate substances that you might find in your water.

A look at all the parts that come with the system. Included are a couple of backup connectors  the dirty bag  a filter  water bottle adaptor & lid  and a bag with the instructions.
A look at all the parts that come with the system. Included are a couple of backup connectors, the dirty bag, a filter, water bottle adaptor & lid, and a bag with the instructions.

The 0.2-micron hollow filter cartridge will rid your water of stinky substances, protozoa, and bacteria. We tested this while group camping on the Gunnison River that is ripe with high levels of sediment and contamination of protozoa and bacteria that could potentially make our group sick. Thankfully, like most places in North America, this gravity filter proves to perform flawlessly.

Water filtered from dirty to clean. While it removes everything you'd need to worry about in North America  it can't remove viruses.
Water filtered from dirty to clean. While it removes everything you'd need to worry about in North America, it can't remove viruses.

It's important to note that like all the filtration systems tested in this review, the pore size is not small enough nor ionically charged to remove viruses, heavy metals, pesticides or microplastics. So, if you plan on traveling to areas where this type of pollution is rich, this is not the filtration system for those trips. Though, anywhere in North America or where these pollutants are not typically found in water sources, it works well.

Get clean water in minutes!
Get clean water in minutes!

Durability and Maintenance


This gravity system offers a high level of durability with only a little bit of maintenance. The filter itself is one system, without any moving parts or complexities. This makes it less likely to fail in the field.

A look at the durable underside of the reservoir bag. This does well to hang against spiky tree trunks or to simply set on the ground when it is needed.
A look at the durable underside of the reservoir bag. This does well to hang against spiky tree trunks or to simply set on the ground when it is needed.

The bag is composed of a thicker plastic composite that seems resistant to punctures and tears. When filling up the full 10L, we were a little worried about the seams splitting, but the RF welding is super strong and reinforced enough to uphold the weight. On the underside of the bag is a 1000-denier flat base that allows you to set the bag down on rocky or spiky surfaces without worry. The filter itself is also quite durable and built to withstand falls from 7 feet high. Just be sure to avoid freezing, as the cartridge will be deemed unusable if it does freeze.

This burly bag can hold 22lbs of water. It also has a puncture-resistant denier fabric layer on the bottom  preventing abrasion and scuffs.
This burly bag can hold 22lbs of water. It also has a puncture-resistant denier fabric layer on the bottom, preventing abrasion and scuffs.

While on a group camping trip with 20 high school students, a few of the autoflow systems that we had on hand began to reduce the flow significantly. At first, we were a little concerned as this was our only way of water filtration. However, when we simply flipped the filter around on the tube to backflush the system, it started to run at the initial rate again. While they do recommend only a half-liter to flush the system, we'd recommend filling to the half volume of the bag (about 4 liters), then backflushing it with the full amount. It's also important to backflush after every significant use to ensure the filter stays clear….especially in turbid water. After we ensured this type of maintenance, our filtration system remained reliable and efficient. This filter works for about 1500L before it needs to be replaced, according to MSR.

A look at the clip that secures the bag to the anchor point. While the plastic is questionable  it sure is burly enough to hold this weight.
A look at the clip that secures the bag to the anchor point. While the plastic is questionable, it sure is burly enough to hold this weight.

Treatment Time


We love this system because you just need to load up the bag, hang it high, then let it do its work. When measuring treatment time, we filtered a liter of water three times, then averaged how fast it took to make one liter of water. In the field, we wouldn't really think about this much, as we'd set it up in the morning and walk away. By the time hiking time came, we'd fill up and be on our way.

Sit back & relax! While this filtration system is similar to other gravity filters  it takes time to filter water in this unit.
Sit back & relax! While this filtration system is similar to other gravity filters, it takes time to filter water in this unit.

Depending on the clarity of the water, treatment time does change. With normal tap water, we measured one liter to take about 2 minutes. This would vary with how full the bag was. The more full the bag, the faster the flow. As the bag emptied, the flow rate began to decrease. Also, when more sediment was in the water, the flow rate decreased to about twice the time and required many backflushes. This was a pain when trying to filter 10 liters.

The space between the bottom of the bag and the intake provides a place for sediment to settle out. This is considered the "sediment trap" that works really well with turbid water.
The space between the bottom of the bag and the intake provides a place for sediment to settle out. This is considered the "sediment trap" that works really well with turbid water.

But since we had time in a group setting, we typically just walked away and had a reservoir of clean water waiting for use when we came back to check it. In general, this is one of the slowest treatment times we observed between all the gravity filters and other filtration systems. However, when testing it for use in a group setting, where time wasn't of the essence, it worked perfectly.

Weight and Packability


The components of the system are all stored in a convenient bag that takes up very little room in a backpacking backpack. From the point of view of a backcountry guide, who typically carries more backup gear for a group, this system proves to be very convenient. It packs easily into cracks and crevices, while the weight is minimal. The bag rolls up, with the receiving reservoir either being a water bag that you might bring along a water bottle, or a dromedary. All in all, it's lightweight and packable.

One of the heavier gravity filtration units tested in this review.
One of the heavier gravity filtration units tested in this review.

Ease of Setup


Set-up on the system is easy peasy. To collect water, the reservoir has a roll-top architecture that requires you to get to a water source and either plunge it into the water or hold it across running water. The downside of such a huge bag is that it's really difficult to collect from shallow and stagnant water sources. Tall banks require you to hover over them to try and reach the water.

Scooping up water is no problem with this reservoir. Shallow and inaccessible sources make water collection difficult.
Scooping up water is no problem with this reservoir. Shallow and inaccessible sources make water collection difficult.

If the water is full of sediment, allow the water to settle for a few minutes before filtering. The bag comes equipped with a 'sediment trap' that effectively allows the sediment to settle underneath the output for the water to be filtered. A cool feature that we appreciate - especially in the desert.

A look at how much water you can get in about 8 inches of water  in one fair swoop.
A look at how much water you can get in about 8 inches of water, in one fair swoop.

Once the water is collected, simply roll the top down and clip it onto a very sturdy surface. A 10-liter reservoir filled with water weighs about 22 lbs! It's important that you find a surface that can support it. We also tried placing it on a sloping hill. This works too, but the flow rate decreased dramatically.

A look at the set-up with a dromedary  designated as our clean-bag for the group. While this doesn't come with the system  we do appreciate the different ways that one can collect water.
A look at the set-up with a dromedary, designated as our clean-bag for the group. While this doesn't come with the system, we do appreciate the different ways that one can collect water.

From here, clip in the tube, attach the filter in the correct orientation (as per the picture), then connect your receiving reservoir. The set comes with an attachment for a standard wide-mouth (think Nalgene!) bottle.

Set-up your filter just like this. If you need to clean it  simply flip it around.
Set-up your filter just like this. If you need to clean it, simply flip it around.

While we appreciate this attachment, we learned that it must be used when the bottle is upright. The attachment can't be screwed on completely as oxygen can't be vented, and thus the water doesn't flow through the filter. Another favorite that we like to filter into is our MSR Dromedary that has the option for a tube plug-in attachment. Overall, set-up is more cumbersome than other, simpler setups, but pretty easy for a system that filters 10 liters of water at once!

Ease of Filtration


This is a gravity filter! Once the system is set-up, all you need to do is sit back and relax. If you attach a dromedary or reservoir that is less than 10L in size, the system will stop filtering if the system is closed. In addition, if you want to stop the filtration process, simply use the hose clamp to do so.

Drip  drip  drip. Actual filtration requires no work. Simply wait for the bottle to fill.
Drip, drip, drip. Actual filtration requires no work. Simply wait for the bottle to fill.

Value


The quality and lightweight characteristics of this system make it well worth the value. For the price, you'll be buying a gravity filter that is easy to use, practical, and durable. With a 1500L filtration capacity, you're looking at about 150 uses for ten people.

Taking this group of students camping means needing clean and healthy water. The MSR XL proved to be the perfect set up for our group.
Taking this group of students camping means needing clean and healthy water. The MSR XL proved to be the perfect set up for our group.

Conclusion


The MSR AutoFlow XL is a 10L gravity filtration system that is renowned for its easy set-up and large capacity. While it does require regular backflushing, especially in turbid water, it's the perfect filter for large groups or guided use. Just be sure that you can hang it in a place that can take the weight of 22lbs of water. This notable mention is our recommendation if you're seeking a system that can make a lot of water for a large group of people.

Using the large-capacity 10-L bag to provide filtered water for 10+ people on a three-day backpacking trip in Colorado.
Using the large-capacity 10-L bag to provide filtered water for 10+ people on a three-day backpacking trip in Colorado.


Amber King