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Reviews > Water Treatment > Filters > Platypus GravityWorks 2.0 L Filter > Owner Review by Ray Estrella

Platypus GravityWorks 2.0L Complete Kit
By Raymond Estrella

July 12, 2014


NAME: Raymond Estrella
EMAIL: rayestrellaAThotmailDOTcom
AGE: 53
LOCATION: North Western Minnesota, USA
HEIGHT: 6' 3" (1.91 m)
WEIGHT: 213 lb (96.60 kg)

I've been backpacking for over 30 years, all over California, Minnesota, and many western states. I hike year-round in all weather, and average 500+ miles (800+ km) per year. I make a point of using lightweight gear, and smaller volume packs. Doubting I can ever be truly ultralight, I try to be as light as I can yet still be comfortable. I start early and hike hard so as to enjoy the afternoons exploring/chilling. I usually take a freestanding tent and enjoy hot evening meals. If not hiking solo I am usually with my brother-in-law Dave or my twin children.

The Product

Manufacturer: Cascade Designs IncBoxed
Web site:
Product: GravityWorks 2.0L Complete Kit
Year manufactured: 2013
MSRP: US $109.95
Listed weight: 11.5 oz (325 g)
Actual total weight: 11 oz (311 g)
Clean reservoir weight: 1.2 oz (34 g)
(In case it is used with smaller bottles.)
Dirty reservoir weight: 2.22 oz (63 g)
As I carry it: 6.2 oz (176 g)
Dimensions listed: 3 x 9 in (8 x 23 cm)
Actual dimensions: 4 x 9.5 in (10 x 24 cm)

Quick & Dirty, Nitty Gritty

The Platypus GravityWorks 2.0L Pump-free Microfilter system Complete Kit is the easiest to use and fastest filtering solo gravity system I have. It works fine for my groups of three when the kids are along too. The most "universal" filling adaptor I have ever seen adds functionality. And as good as it is, I just had to mod it to make it a lean mean filtering machine. Please read on for the details.

Product Description

The Platypus GravityWorks 2.0L Pump-free Microfilter system Complete Kit (hereafter referred to as the GravityWorks or filter) is lightweight pump-free filter aimed at both weight conscious solo backpackers and small groups. A smaller version of Platypus's GravityWorks 4.0L Microfilter system the company uses the Hollow Fiber technology first seen in the MSR HyperFlow filter, and later the first generation Platypus CleanStream gravity system.

The way the technology works is like this. Think of a sealed-at-one-end glass straw with a bunch of little holes in it. As water is pushed against the side of the straw anything bigger than the holes is trapped outside while everything else passes into the straw and out the other end. In the case of the GravityWorks there are thousands of straws with hundreds of thousands of 0.2 micron holes to stop the bad stuff like Giardia and cryptosporidium that can be found in back-country water sources.

Rather than use a pump to force the water past the filter the GravityWorks uses gravity to do the work. A 2 L BigZip bag clearly marked Dirty holds the suspect water. The dirty water reservoir has a quick disconnect that matches up to a silicone tube that goes to the inlet end of the grey filter cartridge. The Dirty reservoir has a thin nylon strap that allows it to be hung from.

All the parts for clean water bliss

At the outlet end filtered water goes through a clean tube to a Clean reservoir that is just a standard 2 L Platy Bottle, like I have been using for many years (see review). It has a small opening about the size of a pop bottle. This will accept any type of Platypus cap or tube, and a Platy Sport Cap (push-pull closure) comes with the system.

A pressure clip on the clean tube allows the flow of water to be stopped at any time. The tubes end fits all Platypus containers so the GravityWorks can be used with any of their big Platy Bottles or hydration systems (Hoser, BigZip), and the system may be used with their smaller bottles too like the SoftBottle or PlusBottle (all of which I have reviewed here).

A black dual compartment storage bag is provided. One side is made of solid ripstop nylon and is meant to hold the "clean" parts. The other side has a full mesh panel for the wet "dirty" parts. A Tyvek-type pull out sheet is attached to the mesh side with printed and graphical instructions for use. When packed the whole works is about the size of a Nalgene Bottle, but I take just the bare minimum, forgoing the storage sack, and get it a bit smaller.

Packed up their way, & Ray way

The kit comes with a bunch of extra parts to make it play well with others. Universal Bottle Adapter that, as Platypus says, "connects with a wide range of hard bottles, including Platy Bottles and most from MSR, Nalgene, Kleen Kanteen, Camelbak and many more". This multi-function adapter will screw together to take as little space as possible and depending on what need it is filling (or what bottle it is filling…) may use just one or a few of the pieces. There is a great piece that lets it fill every type of hydration tube I own (four brands right now) by just pulling the bite valve from the hydration system. This lets the bag stay in a pack if desired.

To clean the GravityWorks is pretty easy. Just fill the clean reservoir and then lift it above the dirty reservoir, while dropping the dirty reservoir down to ground level. If the clean reservoir is allowed to run dry it will get air in the filter resulting in a horrible vapor-lock making it very difficult to back-flush. The trick is to do the reservoir position swap while there is still water flowing into the dirty side of the filter. Now the water runs smooth and the pressure of the clean water back-flushes the cartridge, popping the stuff caught in the tiny holes back out and into the dirty reservoir. Now dump that water and the GravityWorks is ready to go again.

Field Conditions

On table

I used the GravityWorks 2.0L system on almost all of my 3-season hikes in 2013, and a few this year. All use was in the state of Minnesota (MN) including numerous backpacking trips to the Halstad/Hendrum areas on the Red and the Wild Rice Rivers on my side of the state (west), plus trips to Itasca State Park, Chippewa National Forest and Paul Bunyan State Forest (like in the pic above where it is on the table) for a total of at least 23 days. Temps encountered ran from lows of 32 F to highs of 80 F (0 to 27 C) with a lot of rain, some hail and even snow once.

But the best trip I had it on was a backpacking trip with the kids on the North Country and Halverson Trails. You can see it in the background at our camp on Halverson Lake.

Working behind us


I have to thank Cascade Designs for introducing me to gravity systems. Back in April of 2009 I bought their first system, the CleanStream. I became an instant fan, and many of the (rare) folks I hiked with since then have been turned on to them by my systems too.

The best thing about the GravityWorks is the ease of use. No more sitting and pumping until my forearms ache to fill bottles. Just fill the dirty bag and go work on something else in camp while it filters. But I don't need to be gone very long as this thing is a speed demon. I have timed it at 40 to 45 seconds per liter (33 fl oz) in the field.

Filling bottle or Hoser

My preference for carrying water is in a Platypus Hoser which works perfectly with the GravityWorks 2.0L. I have never taken the new Platy Bottle that came with the system in the field as I already have so many of them, plus just use a Hoser bottle along with a smaller SoftBottle or PlusBottle in camp. So with all of those I can just screw the bottle to the GravityWorks and walk away. But sometimes I use one of my beloved AquaFina bottles or a Nalgene when I want to mix something, or plan to carry water in a side pocket. For these I don't bother with the Universal Bottle Adapter, but just fill straight into my bottle as I hold it. The high filtering speeds keep it from being a boring chore.

I will say one thing about the Universal Bottle Adapter. After playing with it at home with everything I could drag out of my cupboards and gear drawers I think that it is the first one to truly be called "universal". I have owned many multi-function fillers and none of them have ever been able to work well with more than two or three styles. I had it on around a dozen different types of bottles and hydration tubes/openings. It really is well designed. I just didn't need it in the field as I was an early adopter of Platypus and continue to be a huge fan.Which water would you pick?

With the BigZip opening on the dirty reservoir filling is pretty easy. I just scoop up lake water or hold it under a running creek or river. Sometimes I have to use a separate water collection device like a collapsible bucket or the company's Water Tank (see review) as a settling container to allow dirt and debris to settle out first. This makes the filter last longer between back-flushing and I am sure extends the life of the cartridge which Platypus lists as 1500 liters. Really I don't know why it would not be more as long as it still can be back-flushed enough to get a good filtering flow once more.

And do I ever run into dirty water. I live on the very western edge of northern Minnesota. It is very flat here and is mostly agricultural. Rains flow through fields and into the rivers and creeks which are brown year 'round. Only as I get into central Minnesota (my preferred hiking grounds) do I run into cleaner water. Even though I collect water in a bucket or WaterTank as soon as I make camp, it still is quite dirty from fine dirt in suspension. As seen below I am camped on the Red River of the North, or Big Brown as I call it. The picture on the left is my "settled" water after being poured into the reservoir. (This is a different one than what came with it. More later.) Then a shot on the right of it in action. Up above can be a side-by-side comparison of the water in the raw and filtered states. The GravityWorks does a great job of cleaning the water up. And it must do a good job of getting the nasty bugs out too as I have never gotten a water-borne illness and I live in the state with the highest concentrations of beavers I think. There is a reason that Giardia is called beaver fever. Those dang things poop everywhere in the water here.

On the dirty Red River

I have made a couple modifications to the system. For one the attached strap works well to hang the bag over a branch, but I have learned that a longer nylon straps gives me many more options for hanging the GravityWorks. I can strap it around a tree trunk when no branches are available, or I can loop it over a boulder. I can flip it over a high branch that would be unusable otherwise. So I added a 48 in (122 cm) strap. Also, we have lots of ponds, I mean small lake/mosquito breeding sources, here. Because pond water can taste pretty bad even though it is safe to drink I have added a carbon element in-line filter made by Platypus to cut the green-water funk. (See review.) And I replaced the dirty reservoir and its quick-connect hose with a Platypus 3 L Hoser bag and tube. I cut the bottom of the Hoser out for a fill spot. I can fill and carry it by its hang loop. I just use whatever size Hoser Hydration bag I am carrying for that trip as the clean reservoir, filling it straight through its drinking tube. This gives me a total system for only 6.2 oz (176 g) of weight and is small enough to just carry in the top of my pack lid when dry, and in a side pocket if wet.

Modded GravityWorks

If there was one thing I would like to see on the GravityWorks systems it would be a faucet back-flush adaptor. I have used them with other systems and it is really the only thing I would like added to this. Otherwise it is a sweet little filter that I plan to use a long time. I will probably get a replacement filter just because of the astounding amount of crud I run through it on the west-side trips. I leave with a shot of the wrapped up modded system sitting in my tent vestibule on a rainy day. As may be seen I just filtered a big Hoser of water for the evening.

In tent

This report was created with the Report Writer Version 1.5 Copyright 2014. All rights reserved.

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