The Platypus GravityWorks filter has easily become my favorite water filter system mainly for its quick filtering and ease of use - these arms won't be pumping any more! It's versatility and efficiency easily warrants the slightly steeper price tag.
Where To Buy
Pros
No pumping
Easy to use
Light and packable
Quick filtering ability
Great for group backpacking
Doubles as shower/sink at camp
Cons
Pricey
Needs large clean source of water
Extra care to keep filter from freezing
Hands need to get wet and cold
How to Use
Setting up the filter is super quick and easy.
The dirty bag needs to be filled, and this can be done by scooping several times in a lake or river. The drawbacks to this method are:
There is no avoiding your hands getting wet, which can be less than ideal if its very cold out
This can only be used if the water source is relatively large and clean, otherwise it would be hard to scoop liters of water into the top of the bag or the filter might clog.
The dirty bag is then sealed at the top with the ziplock closure, and the tubing to the filter easily clicks into the bottom of the bag.
The bag is then hung from a branch or can just be placed on a rock as long as it is above the clean bag. The output tubing connects to the clean reservoir bag via a screw top, which is also compatible with any normal platypus hydration reservoir.
You can then leave it alone and go do something else, and in a couple minutes the clean bag will be completely filled! Occasionally there will be too much air in the clean bag that will stop the flow of water until it is released.
Backwashing
Sometimes the filter can get clogged and slow down the filtering, so when initially starting to filter, reverse the flow of water (hold the clean bag above the dirty bag) for a few seconds until the bubbles decrease, and then continue filtering as normal.
Filter Care
One thing to note with this filter system is extra care is needed to make sure the cartridge doesn't freeze and ruin the filter. This just means I'll bring the filter cartridge into the tent with me at night, or if I think the temperature will drop close to freezing overnight, I'll actually sleep with it in my sleeping bag.
Versatility
One of the main draws of this system is the extra benefits the two reservoir bags provide.
Capacity
When bringing this water filter, I never have to pack extra water bladders, since the Platypus GravityWorks has a total capacity of 8 liters. We will scoop and filter once to fill the clean bag, then we will scoop to fill the dirty bag and head back to camp with 8 liters of water. We can leave both bags hanging overnight, and once the clean bag is used up we re-attach the filter, and in a few minutes we have another 4L of clean water.
A Camp Faucet
Leaving the tubing attached to the clean bag and use it as a kitchen sink for cooking, dishes, or cleaning. There is a black clip on the tube that can help control the water flow, and having this 'faucet' definitely makes camp seem a lot more homey.
Comparison to Other Pumps
I used to have the Katadyn Hiker water pump, which I purchased for $49.99 during an REI sale. This was a great first water filter/budget buy, and it served me well on several backpacking trips. But during trips with groups of 3 or more, pumping water would take a lot longer, since each liter would take a couple minutes.
Also, towards the end of my filter's lifecycle, pumping became increasingly harder physically, and we'd actually have to trade off because our arms would get so tired.
The Katadyn pump is a reliable and great buy for the casual hiker, but since switching to a gravity-driven system I will never go back to pumping ever again :)
Portability
Weighing just under 12 ounces, the entire filter system fits in a bag that is compact enough to not take up much room in a daypack.
Durability
Both reservoir bags are made of a plastic thicker than the normal platypus hydration reservoirs and seem they would hold up well in rugged conditions. The zipper is easy to seal (we all know the ziplock struggles), and the entire system has pumped quite a lot of liters of water over the past year without any noticeable slow down.
I was worried about the inside of the bags growing mildew since I never let the bags dry before rolling them up to pack away, but the inside of the bags are still spotless, odor-less, and mildew-free today without any extra cleaning or maintenance.
I would consider purchasing the backup reservoirs if you're going on a longer trip, as I have accidentally punctured mine from a sharp rock, and having an emergency reservoir is always a good idea.
Overall, a very durable and reliable system.
Final Thoughts
The Platypus GravityWorks Water Filter System has become one of those pieces of gear that makes me happy to pull out to use. Perhaps it is because I've had water pumps in the past that were exhausting to use that it made me realize how great a pump-less set up is (seriously game-changer). I love the versatility of having 8 liters of water at camp at all times, and the entire system feels simple yet reliable.
If you backpack more than once a year or go on trips with more than two people, you might consider investing in a pump-less system like the Platypus!
2018 Update: It's been two years since I purchased this system, and I have had to purchase a set of replacement reservoirs (45$) to replace a punctured bag. The bag was punctured by accident while laying on its side on a sharp rock, but I still stand by the resilience of the system as that was caused by user error. I still think carrying a backup reservoir bag is a good idea!
Disclaimer: This is not a sponsored post, all products were purchased with my own money. This post does contain some affiliate links. What this means is I might receive a portion of the sales, at no cost to you. If you choose use them, thank you for your continued support!