Our Review: Platypus GravityWorks Filtration System 6L

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This is a part of our review series, where we give detailed reviews of all of the gear that we use on our trips. You can see the full list of gear here.

Ever tried to drink water straight from a river? I know it’s tempting, but trust me, it’s not worth the risk. Waterborne pathogens like Giardia can lead to severe abdominal pain, diarrhea, and vomiting. Not exactly something you will want to experience while out in the backcountry. 

This is where a filtration system like the Platypus GravityWorks Filtration System 6L comes in real handy. This water filter system is fast and easy to use, allowing you to get back on the trail with clean water quickly.

So is it worth adding a Platypus Water Filter to your hiking arsenal? Well, we sure do. In fact, we bring it on all of our backpacking trips so that we always have fresh, filtered water on the go.

women's backpacking trips

We get so many questions about water filtration, so we put together this complete review of our favorite filtration system. We go over all of the details and what to look out for when shopping for your own so that you’ll be prepped for your next backpacking trip.

Overview: the Platypus GravityWorks Filtration System 6L

Perfect for: Outdoor enthusiasts, campers, hikers, trekkers, and overseas travelers alike.


  • Easy to set up and use, simply fill the upper reservoir with water, and let gravity do the rest.
  • Clean water on demand, GravityWorks filters up to 1.75 liters a minute without the need for pumping.
  • Removes 99.9999% of bacteria and 99.9% of protozoa, making this filtration system perfect for camping and hiking.
  • Made in the USA using BPA-free and FDA food-contact safe materials.
  • Comes with a “useful life” warranty.


  • Because of the small neck size, the system’s clean bag reservoir can be difficult to clean and keep dry.
  • The clean bag reservoir can be difficult to zip lock shut, particularly with cold hands or if the zip lock track gets dirty.
  • The microfilter lifetime is only up to 1,500 liters of water. Far less than other filter brands.
  • The filter doesn’t remove viruses. So if you were hoping to take this on an overseas trip where exotic pathogens are an issue, perhaps this isn’t the best option.

Who the Platypus GravityWorks Filtration System 6L Is For

The Platypus GravityWorks Filtration System 6L is the easy way to get great-tasting drinking water on the trail. Perfect for those hikers and trekkers that would rather not stand around pumping and squeezing reservoir bags for clean water. Using innovative technology, Platypus has created a gravity-powered filtration system that eliminates the need for straining and hand cramps just to get a drink of freshwater.

Simply fill your bottle or hydration reservoir with tap or stream water, and let it work while you’re doing something else like setting up camp. No pumping is required; gravity doing all the work.

Platypus GravityWorks Filtration System 6L Features


As avid hikers and campers, we needed a water filter that was simple to use and reliable. We wanted to be able to fill the bags, carry them around the campsite without losing any water in the process, and when we were ready to drink or cook with it, we wanted our clean drinking water as quickly as possible away.

To start, the Platypus GravityWorks Filtration System’s main bag requires filling with some stream or creek water. Once the reservoir is filled, it is ready to use. You then connect the second chamber and suction tube at the top (which can be done quickly and with little effort thanks to the clever design) and let gravity do most of the work for you.

Filtration Time

In our experience, this handy system was surprisingly fast. It took us just five minutes to fill bags that would provide 4 liters of clean drinking water. That’s enough fresh water for at least three people (or even four if you’ve been really disciplined with your pack weight).

Water Quality

If you’re wanting clean, freshwater without muddiness or that unpleasant smell that can be associated with water sullied by algae or moss, the Platypus GravityWorks Filtration System will meet your needs. It’s loaded with a hollow fiber microfilter with an absolute pore size of 0.2 microns to filter out bacteria and protozoan lifeforms. In our tests, we loaded this filter up with clear as well as fairly putrid water – and it filtered it all effectively.

Although, it should be mentioned this filtration system does NOT filter out viruses, so if you travel to countries where they are possible contaminants in the drinking water, perhaps it’s best you chose a different option. 


This filter design has been crafted from durable BPA-free and FDA-approved food contact plastics. It’s clear from the engineering that the edges have been reinforced to ensure there are no weak points in this area, which can lead to leaks and tears. 

Although, the hollow fiber filtration element looks a little delicate so care should be taken when handling it. The last thing you might want is to accidentally puncture the walls of the filtration element, which will compromise its function. So for long-term use, it is best put away in a safe storage place for added protection when transporting it. Also, we wouldn’t recommend it be exposed to extreme weather conditions that may affect its use or water filtration capabilities.

Ease of Maintenance

Overall, maintenance of the Platypus GravityWorks Filtration 6L System is incredibly easy. It only requires the occasional rinsing or backflushing to keep it filtering well. However, there are specific things you need to watch out for when using your filter that will help maintain its long-term functionality. 

For instance, ensure no large particles make their way into the filter intake, particularly if you’re traveling in arid environments (like deserts or coastal areas.) 

This can become an issue if they make their way through the filter screen. The Platypus Water Filter simply isn’t able to handle this size of debris and it could potentially clog up the inside of the filtration element. The best way to avoid this is to only refill your bag after it’s nearly empty, wait until all particles have settled out, then backflush until water runs clear again.

Product Size and Weight

This is a lightweight and portable gravity water filtration device that won’t take up too much room in your backpack. Weighing 11.5 oz or around 350 grams, it’s relatively suited to both day hikes and long backpacking trips. 

Measuring in at 10×19.5 inches (260x490mm), the Platypus Water Filter System will roll up and fit snuggly in most backpack front compartments. That way, you won’t have to try and fit an additional pouch on top of everything else you have stashed away in your main compartments already.

Warranty Info

So long as the Platypus GravityWorks Filtration System is used in a manner where the product is properly preserved and maintained, any defects in materials or workmanship will be covered by Platypus’ useful life warranty.

And what is a “useful life warranty”? The Platypus team claim that “your product’s warranty lasts only until it has reached the point where it is no longer safely useful/functional, a point which varies for each product depending on how often a product is used, where it is used, how well it has been cared for and maintained, etc.”. 

women's hiking trip in yosemite


How long does a Platypus water filter last?

Platypus water filters come with a 1500 liter lifespan. If you notice that the flow has seemingly slowed down, flush the filter several times and try to use it once more. If water filters in a timely manner (around 4-6 minutes) the filter is likely still good to use. Although, if filtration continues to be relatively slow it may be time for a replacement.

How to clean a hydration bladder or filter reservoir?

Hydration bladders are best cleaned by hand with hot soapy water. Although, if you are worried about mold, using a tiny amount of dish soap or natural cleaners like lemon juice, vinegar, or baking soda will help keep bladders and reservoirs both looking and working well.

Does Platypus filter Giardia?

Yes, Platypus water filters filter out bacteria and protozoa like Giardia and cryptosporidium. But they don’t filter out viruses, meaning that there are other methods you’ll need to use to purify water that is contaminated by these impurities. With that in mind, it’s a good idea to always travel with Aquatabs, Pristine, or a SteriPen if traveling in areas at risk from such viruses.

Final Thoughts

The Platypus Gravity Works water filter is one of the best water filters we have used for backcountry hiking and trekking. It is very easy to use and requires little effort to produce clean drinkable water. We also like that it is relatively lightweight and compact, making it a great option for short day hikes or long-distance multi-day trips.

If you are looking for a filtration system that is easy to set up, works for large volumes of water, and won’t require a whole heap of squeezing and straining to produce to get clean water, the Platypus GravityWorks Filtration System 6L is a great choice.

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