Katadyn Gravity Camp 6L Water Filter Review

Water filters tend to be heavy and clunky, or too slow and frustrating for regular use. The Katadyn Gravity Camp 6L water filter addresses some of these issues with an interesting design.

No pumping or sucking - hang it up and let gravity do the work  © Richard Prideaux
No pumping or sucking - hang it up and let gravity do the work
© Richard Prideaux

Clean drinking water is one of those things we can easily take for granted in the UK, but as soon as we need to put some effort into sourcing it several times a day small niggles like flow rate, capacity and overall weight suddenly become more interesting. I've used most water filtration and purification techniques over the years on trips, and it is never a task I look forward to. However, this odd-looking filtration system might well become my first choice from now on.

How it works

It looks like a drybag with a hosepipe sticking out of it – and that's pretty much what it is. You fill the 6-litre roll-top bag with water from your suspect water source and hang it from a branch, connect the supplied hose via a quick-connector and release the clamp to start the flow. That is it. As the name implies, gravity does the rest. There's no pumping, squeezing or hanging around waiting for tablets to kill off the biological passengers that threaten to turn the rest of your trip into the toilet two-step.

Filling the roll-top bag  © Richard Prideaux
Filling the roll-top bag
© Richard Prideaux

Two things really impressed me with this system. Firstly, the flow rate. At around 2 litres per minute, Katadyn claim this is the fastest gravity-assisted filter on the market. Secondly, the weight, which makes life easier if you're carrying it any distance. I tested it during a skills training trip in North Wales with a private client, and once the bag was filled it was like having a tap right there in the woods with us.

Effective against bacteria and other nasty microorganisms, the Gravity works even with cloudy water. If you keep the filter protector clean its filter is good for 1500 litres, reckon Katadyn, but when it does reach the end of its life the filter element is replaceable.

Connect the hose to the valve...  © Richard Prideaux
Connect the hose to the valve...
© Richard Prideaux
...release the clamp...  © Richard Prideaux
...release the clamp...
© Richard Prideaux
...and clean water flows  © Richard Prideaux
...and clean water flows
© Richard Prideaux

Where would you use it?

The 6-litre capacity makes the Gravity ideal for small groups or basecamp use (a 10-litre version is also available for bigger groups). Despite its capacity it is surprisingly light (around 350g dry - a little heavier than Katadyn 's claimed 290g) and packs down to around the same size as a pair of lightweight overtrousers. It can easily be filled at a water source and then rolled up and sealed for carrying onwards to camp – I strapped it to the outside of my rucksack, Samwise Gamgee-style. The weight penalty of carrying a water filter can be offset by not needing to carry as much water with you at any one time, but inevitably you will still need more water at night for cooking.

The six-litre capacity is good for groups  © Richard Prideaux
The six-litre capacity is good for groups
© Richard Prideaux
Easiest to use when there's something to hang it from...  © Richard Prideaux
Easiest to use when there's something to hang it from...
© Richard Prideaux

It looks like it was designed primarily as a basecamp item, yet the Gravity is also light enough to make it worthwhile for multi-day backpacking trips or even out on a day walk as an alternative to carrying lots of drinking water with you from the start. Of course the water bag needs to be hung somewhere higher than the container you are using to collect the filtered water – which is great if you have a tree, but will require some creative thinking if you are in the mountains above the treeline. After some experimentation I found that a tripod of trekking poles would work, and even a tent peg wedged into a crack in a rockface. As a last resort you could just recruit a friend to hold it whilst you retrieved the water, or juggle the bag and nozzle carefully to do it solo.

Any drawbacks?

The catch with most water filtration systems is that they are only as effective as your method for keeping the ‘drinking’ end clean. If you know that your water sources are potential sources of cryptosporidium or giardia then there is little point in spending several minutes filtering them out if you still have that contaminated water on the rim of the bottle when you put it to your mouth. This is of course true of the Katadyn system too, to an extent, but they do supply a separate Ziploc bag to keep everything separate in the storage bag. In addition you can always detach the hose via the quick release valve, to ensure that the drinking end stays uncontaminated. The flexibility of the hose means it can be tucked safely out of the way when not in use, and can be connected directly to some hydration bladders too.

The flexible drybag and the filter within seem rugged enough, but only within reason. It could be easily punctured if handled carelessly and would be very difficult to repair in the field, so it may be wise to carry a backup of chlorine tablets.


I really wasn't expecting to get excited about a water filtration system, but this thing has seriously impressed me. It will now be my first choice for extended trips where water sources can't be trusted (most of the remote areas of England and Wales now sadly), and especially for basecamp or expedition use. As long as it is handled carefully it should provide a faff-free clean water solution for a range of users.

I've summarised my thoughts on it in this video:

Katadyn Gravity 6L filter product shot  © Katadyn

Katadyn say:

This sleek, foldable Gravity Camp filter system uses gravity, not your arm, to get the freshest, cleanest water you can always trust. Just hang up the reservoir, fill with water, pull up your chair, and you’ll get up to 2 liters per minute for your entire group. What could be easier?

Maintain the easy-to-clean filter protector to treat up to 1500 liters of safe water. This lightweight system with the Ultra Flow FilterTM does double duty in camp too: An adapter (sold separately) turns it into an outdoor shower.

Dimensions: 25 x 6 x 15cm
Output: 2L/min
Technology: AntiClog Technology with 0.2 micron glassfiber

• Effective against microorganisms
• Suitable for groups up to 5 people
• For solo use
• Suitable for cloudy water
• For daily or very frequent use
• Lightweight and portable for on-the-go adventures
• For travels by motorhome or car
• Stationary use

For more info see katadyn.com

Richard Prideaux head shot  © Richard Prideaux

About Richard Prideaux

Richard Prideaux is the owner of established North Wales outdoor skills training and activity business Original Outdoors. He spends on average one night per week sleeping in a forest, up a mountain or on a beach somewhere in the UK and further afield and the rest of the time teaching navigation, foraging, tracking and other wilderness skills.

For more info see originaloutdoors.co.uk

1 May, 2016
I'm curious about whether this removes viruses?
2 May, 2016
As far as I can tell it will remove protozoan cysts and bacteria but not viruses - currently only purifiers will tackle viruses.
3 May, 2016
This might help, especially the chart showing the various types of filtration/purification. https://www.katadyn.com/en/de/water-know-how/types-of-filtershttps://www.katadyn.com/en/de/water-know-how/types-of-contamination Viruses can be difficult to filter due to their very small size. They are sensitive to chemicals, UV treatment and heat.
3 May, 2016
As Lyon say above- viruses are tough to remove with a filter, but there are some Ultra Filters on the market that will filter down to <0.015microns so remove some if not all viruses, so chemical purification is not the only solution. Sawyer and Lifesver do one. Edit: The Katadyn MyBottle does too. I find manufacturers don't make it easy to compare their products, as they only tell you what they do remove, not what they don't. Independent studies are few and far between, and to be honest it's hard to know how much of a potential problem viruses even are. I imagine that this depends on human population density around the water supply but who knows? If in doubt filter and treat is my approach, but many consumers are just led by what little it says on the box (not suggesting that Katadyn are guilty of this) but I have seen people turn up for expeds with all sorts of unsuitable systems that really don't do much other than remove a bit of colour.
3 May, 2016
It's a massive subject, and as you say, with few independent studies. For manufacturers it is understandable that they will focus on what their products definitely can do though. If I'm travelling to somewhere that I know that viruses will be likely then I will carry chemical purification. Even the very fine filters you mention do not remove all viruses, and it doesn't take much to make you ill. They are also only as good as your own personal hygiene and how good you are at keeping the 'clean' end clean... The viral outbreaks you see on the AT amongst dozens of experienced hikers using good filters show that there are no guarantees. Steripens seem to be another reliable option, so long as you can get the sediment out of the water, but that goes for chemical purification too. Water quality in remote areas is a weird one - I quite happily drank from streams all over the uplands of the UK until we ran a course for staff from Dwr Cymru who told me the results of some random tests they did in Snowdonia. From then on I filtered/sterilised/boiled everything if I had the choice. Agreed on the motley selection of water filtration/purification systems we see. The guy that turned up with a kilo of cayenne powder is still the winner...

Facebook Twitter Email LinkedIn Pinterest