DIY gravity filter bag

[redoleary]

This is my gravity filter system that I use in the backcountry. I made one last summer and was ultimately quite happy with the performance and this year my sister and her family is getting into backcountry camping so I made this for her for their upcoming trip to Boundary Waters. Anyway, it's not a very captivating video (I was even too lazy to put music on it) but it's a system that I find works well. There is a parts list in description below the video.

 

[Guest]

This is my gravity filter system that I use in the backcountry.

I like it. I’m a fan of gravity filters, except for the $100 cost.

What do you think of the Sawyer Filter cartridge?

https://sawyer.com/products/sawyer-mini-filter/

I’m impressed with their 100,000 gallon filtration claim, but a paddling friend had a similar DIY gravity filter with a Saywer cartridge on a trip and it required more frequent cleaning than the simple backwash on my Platypus.

 

[redoleary]

The filter I have is the one just a size larger than the mini, reportedly good for a million gallons, I'll loose it or wreck it before that.... Anyway I'm a fan of Sawyer filters but would bring along a syringe to back flush as necessary. We did 5 days in the Boundary Waters last summer and never needed to back flush had good flow all week, but maybe three years before that I had one of Sawyers purifying filters (filtered even smaller than .02 µ) and it was almost unusably slow by the end of the week, however I don't believe I had a good prefilter system at the time. Fortunately the wife is over the need for purified water and is comfortable with just regular old filtered water now, which makes the filter much easier to maintain. I think the secret to the sawyers is to have a good way to prim the filter before use so the entire inside is saturated, this I do at a faucet before the trip and I use the little end caps to make sure the innards stay wet. I also do a good back flush after the trip with relatively high pressure from the sink.

 

[Murat V]

Cool stuff. If my Katadyn base camp bag ever fails and springs a leak, I'll be whipping together something like this. Thanks for the detailed parts list and putting together a clear vid of the assembly process.

 

[redoleary]

Thanks, I'm always hopeful that my instructions make sense to everyone else.

 

[Guest]

Thanks, I'm always hopeful that my instructions make sense to everyone else.

I thought it was well presented and detailed.

It got me thinking. On family trips or long solos I sometimes bring an extra water filter rig (usually a pump type), or at least a spare filter cartridge. And I always bring a small collapsible bucket.

I could install a sealable port on the bucket and have the spare filter ready to go with the connectors and tubing attached.

 

[redoleary]

Thanks Mike. You could install a bulkhead fitting into the bucket and stick one of THESE in there until you wanted to turn it into a water system.

 

[AlanP]

Great system and presentation

thanks alan

 

[Seeker]

Great video. Thanks.

 

[redoleary]

Great system and presentation

Great video. Thanks.

Thanks guys, really appreciate it.

 

[Bothwell Voyageur]

That's a great mod with the bucket but you don't actaully need to cut a hole in the side. Just find a way of anchoring the end of the hose in the bottom of the bucket and run the hose up and over the side of the bucket to your filter. To start filtering suck on the open end to draw water up and over the top of the bucket and down through the tube to the filter. As long as the clean end of the tube is lower than the bottom of the bucket the siphon effect should keep on pulling dirty water down to the filter.

This was the design used by Ray Jardine in his PCT book. He also suggested that an additional benefit came from preventing contaminated water leaking down along the outside of the hose and down to your drink bottle. I think he actually anchored the filter into the bucket.