Hands-on Gear Review
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Street Price: Varies from $97 - $120 | Compare prices at 5 resellers
Pros: Fastest treatment time, easy to use, relatively light, requires little maintenance.
Cons: No separate storage for clean and dirty hoses, expensive, hard to collect water from small or non-flowing sources
Best Uses: Backcountry trips with a basecamp, General overnight hiking trips, car camping.
After some surprising results in our tests, the Platypus GravityWorks took the lead in our comparison, winning the Editors' Choice award. We initially thought this system would be bulky and time-consuming, but the opposite was true. In fact, this is the fastest system for filtering water, particularly large quantities, is one of our lightest filter systems, and requires little to no maintenance. The filter lasts a long time before replacement (1500 liters), being beaten only by the MSR MiniWorks EX (2000 liters.) Since it easily treats small or large amounts of water, it is the most versatile system, working well for a camp of multiple people, or for a solitary hiker on the move in the mountains. The primary drawback to this system is that is more expensive than the average pump filter such as the Katadyn Hiker Pro or the MSR Sweetwater Microfilter. Also, it does not treat viruses like the SteriPEN Journey LCD or the First Need XL, so if you plan to travel around some very sketchy water, this may not be the filter system of choice.
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OutdoorGearLab Editors' Hands-on Review
The GravityWorks is a unique water purification solution in that it combines filtering with storage. With a 4-liter capacity, the Platypus clean container makes for a convenient and ample water supply for your campsite. This means you can eliminate the need to carry a separate water container for campsite water, saving weight and space. In practice, it is fast, easy to use, and makes campsite water easy to access whether you are solo backpacking or in a group campsite.
The hollow fiber filter in the Platypus GravityWorks is effective against protozoa and bacteria, but not viruses. For what it does sterilize, this is a very reliable system. The absence of moving or electronic parts means that it is less likely to break or malfunction.
Including the storage bag, this system weighs 11.99 ounces, which is the second lightest filter to the MSR Hyperflow Microfilter. This makes this filter a great choice for hiking since it does not weigh you down.
Time Before Drinking
At first, we were skeptical of this system. We thought it would be slow and cumbersome to use, but instead we were quite impressed. This gravity system works surprisingly fast. We timed the filtration process, and it only took 4 minutes 50 seconds for the entire dirty bag to filter into the clean bag in a complete timed test, and 1 minute 5 seconds to filter one liter in a smaller timed test. This is less time that waiting for tablets to work their magic, and actually involves less work for the user than any of the pump systems. None of the pumps will provide four liters of purified water in under five minutes. Even the SteriPEN, which is our next fastest system, takes 90 seconds per liter, which if you do the math, takes six minutes to purify four liters of water, not counting fill times in between sterilizations. Waiting almost five minutes to drink can seem like a pain, but in actuality this GravityWorks system purifies the most water the quickest.
Ease of Use
This system is ridiculously easy to use, even more so than a lot of pump systems. You fill the dirty bag, attach the hoses and with the arrow on the filter pointing towards the clean bag, and set the dirty bag somewhere above the clean bag, which doesn't even have to be very high. This system worked fine with the dirty bag sitting on a rock and the clean bag on the ground, it does not need to be hanging from a tree to operate. After you fill it, you can let it do its thing while you set up camp. We like that the dirty bag and clean bag are clearly labeled, and the dirty bag has an open zippered top, while the clean bag does not, so you will not accidentally mix them up and cross contaminate. The only downside is that the hoses are not as easy to keep separate. Since the dirty hose has the filter attached to it, they are easy to tell apart, but there is no convenient way to pack them to keep the hoses separate from each other.
Durability/Uses Before Maintenance
The maintenance on this system is very low. The filter is good for 1500 liters, which is second only to the MSR Miniworks ceramic filter, so it does not need to be replaced all that often. In the meantime, the only other maintenance required is a quick and painless back-flush when you set up the gravity system. All this requires is elevating the clean bag above the dirty bag for a couple seconds to let air bubbles escape, which is nothing compared to scraping a ceramic filter or reversing all the valves to set up the complicated back-flush on the MSR Hyperflow.
The one thing to watch out for is that you do not puncture a hole in one of the bags, which would ruin the system. However, the bags seem very durable and in our tests we have not had an issue with this.
The water flavor remains unchanged and particulate is strained out of the clean water.
Since this system excels at purifying larger quantities of water, it is well suited to car camping, or backcountry trips that will involve a base camp. Our initial impression was that it would not be as conducive to fast in-a-day backcountry missions where you want smaller quantities of water quicker, and do not want to sit around for five minutes waiting for it to filter. Then we tried it on our own hiking mission and felt that it took only as much, if not less, time to filter water through this system as with a pump. Even though the bags hold a gallon of water, you can fill the system just part way if you are in a hurry and do not want to carry extra water. Our final verdict: it works well in just about any backcountry situation where you would like to filter water, with perhaps the exception of really nasty pools where you don't want to scoop out goopy water.
At $110, this filter is on the expensive side, which seems strange for such a simple system. It costs more than even the SteriPEN with its high-tech UV light. This system is excellent to use and works very fast, so it may be worth the investment, but expect to shell out a few more dollars for the luxury that the gravity system provides.
In the end, we felt that the GravityWorks was the best water purification system available, and the one we'd recommend to friends and family for general use. If you are looking for one water filter that can serve your needs, whether car camping or backpacking, this is the one we'd pick. And, that's why it earned our Editors' Choice Award for best water filter.
There are other gravity style filters on the market, which are likely to be as low-maintenance as this system.
For 2013, Platypus is offering two different kits for this filter, a Bottle Kit and a Complete Kit. They both come with a bottle adapter that makes it easy to filter directly into a water bottle or water reservoir without removing it from your pack. This new offering makes this filter even faster and more convenient than the edition of this filter we used for this review.
— McKenzie Long
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OutdoorGearLab Member Reviews
Most recent review: May 7, 2013
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