GravityWorks 4.0L Filter System
Out of Stock
Don't worry though, we have a lot more Water Filters & Purification in stock than that.
Shop Similar ProductsWhy We Like The GravityWorks 4.0L Filter System
The GravityWorks 4.0L Filter System is pretty dang easy to operate, and there are plenty of devotees who can't get enough of the world's simplest water filtration system. Just fill one of the Platy Zip bags with water, place it above the empty bag, open the hose clamp, and let gravity do the rest. In 2.5 minutes, you'll have four liters of clean water, and if camp is far away, fill the other bag to carry back with you. Open the hose clamp to dispense water, and shut it to stop the flow. To clean, simply reverse the bags for four seconds, running water through the filter in reverse. That's seriously it.
Details
- Gravity filtration system ensures effortless filtering while backpacking
- Two 2L bags for dirty water suspended over one another for auto filtration
- Filters 4L in 2.5 minutes without any need for pumping
- Shut-off valve eases control when filling up water bottles
- Reverse-flush cleaning takes four seconds
- Item #CAS001G
- Purifying Element
- hollow fiber
- Eliminates
- protozoa, bacteria, particulate, giardia, cryptosporidia, E. Coli, salmonella, cholera
- Filter
- hollow fiber
- Pore Size
- 0.2 microns
- Cartridge Life
- 1500L
- Action
- gravity
- Volume
- 4L
- Flow
- 4L / 2.5min
- Field Cleanable
- yes, backflush
- Dimensions
- 3 x 9.5in
- Claimed Weight
- 10.75oz
- Manufacturer Warranty
- limited
Reviews
Q&A
What do you think about this product?
Overall Rating
4.5 based on 138 ratings
Review Summary
Fits True To Size
Screen reader users: the following list provides a visual scale to illustrate the product fit. Please refer to the heading above for the fit type in text.Customer Images
View
Selecting an option will reload the available reviews on the pageSeptember 12, 2024
Never Pump Again!
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?
Originally reviewed on a Cascade Designs brand site
August 27, 2024
Season 2: Disappointed
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.
Originally reviewed on a Cascade Designs brand site
August 14, 2024
5 Trips to the backcountry
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.
Originally reviewed on a Cascade Designs brand site
July 1, 2024
Fantastic!
I have used both the 4L and 6L for hiking groups with scouts in tropical Australia over the last 5 years. I went from the 4L to the 6L only because I accidently lost the 4L! :-( It has high usage with up to 10 people using it over 2-4 day hikes, 2-4 times a year. I follow the long term storage instructions and the filter cartridge has tested fine prior to use in the following season. Without detracting from the 5 star rating, my two gripes are this: 1. there should be another flow clamp on the dirty side of the filter for those occasions where 6L has been filtered but more water has been added to the dirty bag - this would allow flow to the filter to be stopped when the clean hose needs to be disconnected for use. As it seems the clamp cannot be purchased by itself (only part of a hose replacement kit), I have used a plastic clothes peg to crimp off the line as a solution. 2. the zip-lock on the top of the dirty bag can be incredibly hard to squeeze shut and it is even more difficult for youth who are trying to do it. Sometimes if it isn't quite done, when the bag is picked up, it will pop open. A fold over system with a slider to seal the top as can be found on 'Osprey' water bladders, or the top of a dry bag would be a far easier design option to use in the field. Overall, an amazing, functional system.
Originally reviewed on a Cascade Designs brand site
April 21, 2024
Filter stopped working
When I originally purchased the 4 liter filter I used it a total of maybe 3 times, always backflushing, and correctly storing it. Next season when I pulled my filter out it was already showing bubbles when doing an air push so filter is already broken. Went and bought a new filter which I used for the first time today and water doesn't come through. I soaked it and now it trickles like 1 liter in 10 minutes. I can't believe how fragile these filters are and how some people have been using them for years when I can't even get one to work once.
Originally reviewed on a Cascade Designs brand site
March 28, 2024
Great Filter with less effort
I have had the 4L gravity system for 5 years now and just upgraded to the 6L system. I love this system. I do carry a backup filter and have had to use on one occasion due to my filter being clogged because I did not backflush at all for a couple of trips. I did backflush at a later date at home and this original filter was back up and going good. The original 4L dirty bag is coming apart at the top now but I have use so many times I feel that I have gotten more than my money’s worth. I have put this thing through the ringer for years. I do clean per the instructions included before storing. Another great thing about this system is you can carry water in the clean reservoir with a simple plastic bottle cap. I have done this several times on top of my pack when on ridge’s requiring water to be packed in. I have tried some other methods and this is the best I have found. We typically hike 40-80 miles a year and this has been a wonderful asset out there. Happy Hiking
Originally reviewed on a Cascade Designs brand site
November 18, 2023
Questionable reliability
I purchased a 4.0L Gravityworks filter back in 2022 and was initially exceptionally pleased with it. Used it the summer of 2022 and was quite happy with the results. I followed the instructions to a “tee” at the end of the season when putting away for long term storage. When I pulled it out May/2023 I didn’t test it beforehand (I should have, that’s my fault). But I hiked up into the bush and when I got to the camping area I went to get my water. I filled the dirty reservoir, and made all the necessary attachments to the clean bag. Zero flow. None. The water wasn’t penetrating the filter at all. I was mortified at the catastrophic gear failure. I always backflushed, had used the filter only sparingly and, as mentioned, followed all instructions for long term storage. So I was forced to boil water for my drinking and cooking needs. Not an ideal situation, particularly since I’d only brought so much fuel. I was able to boil enough water for my needs for two nights in the bush but it was a labour intensive undertaking that should have been avoided but for a clogged filter. After that trip I purchased a replacement filter and took it on a six day solo hike of the North Coast Trail. On night one it worked like a charm. Super fast flow and I had eight liters of water in about 10 minutes. During the trip I always made sure to back flush after every other filter. Nevertheless by my last day the filtering process took considerably longer than that first day. Eight liters was taking me about 30-45 minutes to filter. I’ve just stored the filter away for the winter (per instructions ) and will test it again before my first hike in spring 2024. I want to like this filter, I really do. When it works it works well, it’s lightweight, simple to use and takes up remarkably little space in the backpack. But my experience to date has made me nervous to rely on it, particularly during multi day through treks. As such I believe my experience to date warrants a three star rating.
Originally reviewed on a Cascade Designs brand site
November 10, 2023
Looks like it could be a great filter, but mine doesn't work (details below)
I picked this up a couple months ago thinking it would be great for canoe camping. Unfortunately there must be something wrong with the unit I received. I can barely get a trickle of flow through. I tried all the backflushing tricks that are suggested in case the issue was air bubbles trapped in the filter, but only got a trickle of flow on the backflush too. I also did the filter integrity test but I wasn't able to see bubbles coming out so I know that isn't the problem. And of course it's brand new so it can't be from sediment build up. And it's been on a shelf in my closet so no drops/freezing. Finally after fiddling with it for an hour I took the end caps off the filter to see if there was visible damage to the hollow fibers. There isn't (as far as I can tell) however there is a film (almost like glue) covering the end with all the little hollow fiber tubes. I don't know if that film/glue is supposed to be there, but in my case it seems to be blocking all water flow through the filter. Barely any water makes it through that film. Anyways, all that is to say that my filter doesn't work. And unfortunately I lost my receipt so return/warranty isn't an option. Now I have to decide if I by a replacement, or just go to another brand. I definitely don't want this to happen again given how much the filters cost.
Originally reviewed on a Cascade Designs brand site
November 8, 2023
Great Inline Gravity Filter
This is the first gravity filter system I've owned. I owned pump filters in the past. This purchase was long overdue as it is a tremendous time saver. I've used other people's gravity filters such as Katadyn. I chose this system over Katadyn because of the in line filter. I could use it to suck water out of cracks in rocks if needed which helps bridge the gap in functionality between pump and gravity filters. The only downsides I see to the inline filter over the in bag filter like Katadyn is that it is easier to clean and visually inspect for contamination/clogging with the Katadyn filters. This being an enclosed filter, it is harder to dry out. I often camp in below freezing conditions which can destroy a filter if water freezes in the filter. If and when this happens, I would get a Katadyn filter for winter camping and use the GravityWorks filter the rest of the time. I use alum powder for silty water and it keeps the filter running smoothly.
Originally reviewed on a Cascade Designs brand site
October 30, 2023
Appalachian Trail 2017
I used my 3 stage filter, from Georgia to Maine…5 months 3 days. It never failed me. After the trip, I asked my nephew what his favorite piece of equipment was on our trip…he laughed and said, “YOUR Platypus” he only had the Soyer squeeze. I’ve continue to use it for 6 years.….new filter of course.
Originally reviewed on a Cascade Designs brand site
Do you have a question about this product?
September 7, 2021
Are the reservoirs 2L or 4L each? The description says "Two 2L bags ", but the name and photos suggest it should be two 4L bags.
May 11, 2020