Platypus GravityWorks™ 4L Filter System

Awesome filter for groups and super easy to back flush. I love seeing the dirty water transition into the clean bag. I would 100% recommend.

Had high expectations from reviews, which is not always a good place to start, and came from using tablets not any other filters so I don't know how bad others can be, but overall a good experience. Don't love the ziplock closure (maybe roll top would be better?)

This is the easiest and quickest water filtration system I've used. Four of us biked to Goldmyer Hotsprings for a few days and this kept all of our water bottles filled and cooking was a breeze with this easy system of using gravity.

Fill it and forget it! Great water treatment option for any basecamp.

We've had our 4L GravityWorks system for seven years now (still on the original filter!) and will never consider going back to a pump system. Our typical use is in the Boundary Waters and Ontario's Quetico Provincial Park on 10-day trips. On our last portage before our destination lake for the night we pull the dirty water reservoir out of the storage bag, paddle to the middle of the lake, scoop up four liters of water, then head for a campsite. Before setting up the tent, we hang the gravity filter and we have clean water before gear is in the tent! With proper backflushes, air purges, and cleaning/drying before storage, slow filtration has never been an issue. Only one problem: the black 'cleanside cap' disappeared on our recent Quetico trip. Where do I get a replacement? And shouldn't it be a brighter color?

Used on first trip - year one, worked very well (filter was new)... year two the filter was nearly at a stand still. Not sure why the filter failed after one trip - it was backwashed and stored as per guidelines, and used in pretty clean water on the first trip. Expensive filter for a single use. Maybe go back to MSR pump filter? At least the MSR filter was reliable.

I bought this 6 years ago for an annual canoe trip in Northern Ontario. It works great year after year, I always backflush it before putting it away and have never had any issues. During use it will need to be backflushed every 30 - 40 liters when I notice the flow is slowing down. At this point I've probably ran around 300 liters through it and it still works like the first day.