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3/06/2017 2:24 pm  #1

Gravity Filter Question

Hi - I know a lot of the folks on the forum are fans of the Platypus Gravity Filter system, and I'm hoping you can help me with a question. Do you still carry a pump for those situations when you are traveling in the park, and setting up the gravity filter is kind of impractical?  I can definitely see the benefits of the gravity filter in the campsite, expecially when it comes to things like having water for cooking.  Do you carry any spare parts (is there a weak link to worry about)?

I've always pumped (or squeezed my guts out in the case of the Sawyer mini), figuring I can do that from the canoe or campsite, without being land-bound to do so.  This year the whole family wants to go on a trip with me (YAY!  Except now I have to buy even more capital equipment....yay....), and I'm going to have to do something to obtain a greater volume of water or I'll spend the whole time pumping water. 


3/06/2017 2:31 pm  #2

Re: Gravity Filter Question

We ran into this issue last year on a family trip. We use the Sawyer mini for a 6 of us and with a little focus we made it work. We were essentially always filtering water when stopped or at a campsite. This sounds cumbersome but when there are 6 of you, it's easy to spread the work around. The platypus was filled and started to filter first thing then whenever someone would notice it was empty, they'd fill all the water bottles that were kept close by the "water tree" where we hung the filter and fill up the dirty platypus again for more filtering. 

The fact that it filtered on it's own with gravity meant we could do other camp chores or fun things while it was doing it's thing. 

Re: more gear required for family camping: gear is a huge barrier to people. I'm a big fan of borrowing and lending. If you're ever in the Guelph area and the timing lines up (e.g. we're not tripping either), we're willing to lend out gear. I have borrowed plenty from friends in the past and now I try to pay it forward. It's a nice way to figure out if you need something or like something. 

As long as it's normal wear and tear, I don't get too precious about damage. 


3/06/2017 4:38 pm  #3

Re: Gravity Filter Question

If you are going to be boiling the water, then I wouldn't bother filtering it for cooking. I do use treated water when making things like biscuits or dumplings where I'm not entirely sure that the end product will have reached an internal temperature of over 100C. 

An alternative to filtering is using Pristine. We generally carry 2 1L nalgenes per person. When a bottle is emptied, I'll refill it and treat with Pristine. There's a 15 minute wait time but even on hot sunny days that isn't usually a problem. 


3/06/2017 5:48 pm  #4

Re: Gravity Filter Question

I don't take any other method of water filtration other than my Platypus. I love the thing. Because there is next to nothing to set up and it filters water quite quickly there would be few occasions where it would be truly impractical to set up.


3/06/2017 7:56 pm  #5

Re: Gravity Filter Question

I have a Katadyn Pocket filter and I subsequently bought a Platypus Gravity filter.  I really like both, but you have to earn it with the pump filter.  The gravity filter has a bit of a learning curve to get it to make water quickly, but once you understand it, it does all the work for you, which is really nice on hot days.  With the Katadyn I carry a full set of spare parts, which I've never had to use.  The thing is built like a tank (read: heavy and expensive).  With the Platypus, there's no moving parts, so there's really no spare parts to carry.  As long as you haven't damaged the filter, and have one good water bag (you could always use the 'clean' bag to feed dirty water into the filter and let it run into a pot or bottle) you could make clean water.  If you were really cautious, you could carry a spare filter and extra dirty bag. To me that's overkill, but it's really personal choice.  I always have a backup plan in terms of water, but they're much lighter weight than a second filter.  The only time I've had both my filters on a trip was when I was traveling in a large group (~10) and there was minimal portaging.  Only the gravity filter was used.

One word of advice: if you get a gravity filter like the Platypus, get the one with the larger (4L) water bags.  Even traveling solo, I can make use of 4L.  The extra weight and size of the larger bags is minimal, and the filter is the same.


3/07/2017 2:45 am  #6

Re: Gravity Filter Question

I like to have a backup plan, so in addition to the Platypus I carry several water purification tablets. They weigh nothing and take up almost no room in the pack.


3/07/2017 6:40 am  #7

Re: Gravity Filter Question

I have the MSR miniworks and the Sawer mini. The MSR unit works good but it takes quite a few pumps to fill a nalgene and you have to always clean the filter. With the Sawer mini I attach it to a 6L MSR drom bag using the hydration kit and 3-1 hydration cap from MSR. I hang the drom bag and let gravity do the work. It actually cleans as fast if not faster than the MSR miniworks. No more pumping for me. The Sawer mini drom bag and hoses is less weight than the Miniworks. You still have to backflush the sawer mini. 


3/08/2017 9:35 am  #8

Re: Gravity Filter Question

My canoe partner and I just started using the Platypus Gravity Filter system in camp and we can't find a flaw with it.  We use the lifestraw bottle while traveling, so we don't need to stop and refill.  We find that to work the best for us.


3/08/2017 5:33 pm  #9

Re: Gravity Filter Question

Thank you so much for these wonderful responses.  I've got plenty of time to consider options, sometimes it takes me absolutely forrrreeeevvvveeerrrrrr to make up my mind about something - and the benefit of your combined experience is something I am very grateful for.  And CanoeClaire - your offer to loan equipment does not surprise me in the least.  Thanks!

     Thread Starter

3/09/2017 2:50 pm  #10

Re: Gravity Filter Question

I'll chime in to say I have a platypus 4 litre gravity system and I think it's great. The documentation seems to indicate the filter cartridges are a little fragile, so I have considered bringing a back-up, but haven't executed on that.

The MSR and Platypus cartridges look be identical other than branding.


3/21/2017 8:49 pm  #11

Re: Gravity Filter Question

One important thing to note when using the Platypus - be sure to "backwash" the filter every so often.  This is really important to maintain a good flow.  The only "weak spot" I have with mine is that the eyelets where the handle passes through for hanging the dirty bag REALLY stretch and I think mine will break through during the next use.  It is a bit of a design flaw, but given you need very little height differential to get the filter working, simply putting the dirty bag slightly higher solves this problem (i.e. On a rock)

It is the single best piece of kit I have purchased so far - totally worth the 100 p(or so) bucks. 

I do NOT bring a back up filter, but I do bring a set of drops/chemical treatments as an emergency back up (albeit one I don't anticipate needing).

We take this on group trips (4 to 7 ppl) and one thing we do bring in these cases is a super cheap ($5) collapsible water jug from Canadian Tire.  It has a 20 L capacity and we simply drain the bag directly into that container.  We just keep filtering water until the jug is full.  For groups this size, my experience has been that we go through a full 1.5 jugs per day.  Makes this filter totally worth it.


3/22/2017 12:14 pm  #12

Re: Gravity Filter Question

pjr2013 in case you were not aware Platypus had a manufacturing issue with grommets on the clean bags and they will replace (it was an over the counter exchange for us at MEC) .  This little issue still hasn't detracted for me on how great and easy the system is. 

Similar to others above, I have been on week long trips with 8 people and it was all we needed.  Both tripping families we were with also went out an purchased one to replace their pump after.  Easy in the camp but you can easily filter in the canoe hands free - Fill the dirty bag over the side and rest ontop of a canoe pack with the clean bag on the floor.  Takes a few minutes longer then hanging but an easy way to filter 4L while being free to paddle.



3/22/2017 8:44 pm  #13

Re: Gravity Filter Question

Does anyone use the Aqua Tab water tablets? If not, is it because the $$ will add up over the long-term? The wait period before drinking? The taste? Any other reason?

I've always found the size to be convenient to keep in my pocket, and I haven't had any issues with waiting for it to purify (if I'm with a group, we always keep 1 bottle full, and if I'm solo I just choose wisely when to refill). I bring a collapsable 5L jug that I fill up once I'm at the campsite, drop a couple tablets in, and that's my water for the night/morning.

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3/23/2017 7:25 am  #14

Re: Gravity Filter Question

I have been using my 2 liter GravityWorks system for 2 years now (2015 and 16'). I have done absolutely no maintenance to it what so ever and it still worked flawlessly last December. The flow is obviously a little slower because I've used it on 150+ nights worth of camping and I haven't even changed the filter cartridge yet (ordered a new one from Mec yesterday). I do a quick back-flush before every use (once a day while camping). I took a look at it yesterday and the grommets on the reservoir bag show absolutely no signs of wear, and neither do any of the other parts that came with it. I'm very very happy with my filter and recommend it to everyone! The only reason I got away without changing the filter cartridge in 2 years is because I always get the cleanest water possible. When I fill the reservoir I hold it up and look through the water after I fill it and if I can see anything floating around other than air bubbles I dump it and go for another scoop until I get a clean one (usually not an issue).


3/23/2017 10:45 am  #15

Re: Gravity Filter Question

@trippythings. I use either pristine (sold by MEC,liquid to mix) or the aqua tablets and have for many years. Due to a hodgepodge of older equipment and only about a month a year or so for camping I'm  always short on room when packing and find looking for the pump a pain if it's packed. I tend to do long trips of 14 days or so, and I find it easy to put the packets in my pocket or flap of my back pack for easy reach together with my water bottle that ill refill and treat while padling. once at camp I use the larger water bag from MEC and put the tablets in IT.water bag Packs away like a ziplock.
Never in all those years have I got any nasty effects of the treated water. although there's none to very little after taste, I have well water at home and it does taste slightly different, but after a day I no longer taste it.nmy friend who's from the city and has chlorinated water doesn't taste any difference at all.


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