Sawyer mini filter as a camp gravity system?

If you have old bladders, you just splice the mini inline on the drinking tube and have an on off valve/device of your choice on the very end of the tube. Hang bag, open valve.

Many threads about this

I've used in gravity mode, slow, I forget about it and it overflows onto the ground

Instead, I use 1 liter soda bottle in normal squeeze mode. 1.3 ounces. You can put some pressure on the filter so it flows good.

Flow very slow sometimes in gravity mode or with collapsable bag which I fear squeezing on too hard or it will break.

My experience is quite different from Jerry's. My gravity filter system consists of a 4 liter Big Zip dirty bag, 4' of tubing, the mini filter (or a Frontier Pro if I use chlorine dioxide pills), and a 6" outlet tube that connects to a 2-liter Platy. I use Hyperflow caps on both Platy containers, which twist easily to turn the flow on/off. I remove the bite valves and connect the Hyperflows directly to the tubing. This filters very quickly (2 L. in 1.5-2.0 minutes), due to the 4' tubing. Any length less than ~3' and the flow start to get pokey. No real worries if I happen to be doing other things while filtering, as the system is a closed one, and once the clean bladder fills up, the flow stops. No spills.

"This filters very quickly (2 L. in 1.5-2.0 minutes), due to the 4' tubing. Any length less than ~3' and the flow start to get pokey."

Mine works about the same. The only thing that will disrupt the flow rate is if there is a big air bubble in the filter. If you carry the filter full of water, then this is not a problem. Of course, that means that you are carrying an extra ounce of water weight.

Frontier Pro, Platypus, Sawyer… I see them all about the same.

Has anybody ever figured out how much hose length in the middle is necessary?

–B.G.–

What do you mean, Bob? Are you talking about the tubing length from the dirty bag to the filter? I have learned by trial/error that 42" works nicely. Anything much less seems to slow down the flow rate. Anything longer than 4' is kind of hard to work with, to be able to reach the tree branch to hang the dirty bag.

Also, I have a 3 foot length of paracord tied to the handles of the Big Zip, with a macho cord lock. This allows me to hang the bag by the cord, and adjust the height of the bag from the ground to exactly allow the clean Platy to stand up (with maybe a couple of rocks to stabilize it so it doesn't try to fall over when weighted with water on uneven ground).

I made a gravity filter using the cartridge from a Sawyer Personal Water Bottle Filter. The outlet of my dirty bag has 1.5" of silicone tubing and one of these stopcocks:

http://www.usplastic.com/catalog/item.aspx?itemid=36485&catid=828

Out of that I have 5' more tubing and the cartridge. Sounds like I could shorten that by a foot and not suffer any flow reduction. As it is I get 1 L through in a little less than 1 minute.

The output end of the stopcock is not barbed so it is relatively easy to slip the long silicone tubing on & off, so you can leave the long tube & filter cartridge disconnected while you are filling the bag at the water source.

Wow, it sounds easier than I thought. I'll have to give it a try.

Where do you guys get your tubing?

I have not seen a mini yet… but have the early blue/white or grey (early to me) and the next iteration the black one… I use to use a 5g solar shower and now use a 10L dromedary bag (did not trust the solar shower seams)… the big difference with these systems seemed to not be the head volume or the tubing length (3 feet at least)but the tubing diameter; the shower tube was almost double the dia. compared to the stock MSR tube for the dromedary bag for flow volume and the filter close to the bag…my 2 cents and a pic… have been using the system for 2 years now and when in a group recently 2 hyperflows were carried but never saw the light of day as my system was just easier and faster to use…

"I have learned by trial/error that 42" works nicely. Anything much less seems to slow down the flow rate."

Currently I use about 20" from the dirty bag to a filter, then another 20" from the filter to the clean bag.

I'm just trying to figure out how we arrived at that length. I need to get a lighter weight hose.

–B.G.–

http://www.cascadedesigns.com/platypus/filtration/accessories/gravityworks-hose-kits/product

"Frontier Pro, Platypus, Sawyer… I see them all about the same." -B.G.-

Actually, Bob, the Frontier Pro isn't the same as the other two. Its pore size is larger, and it won't filter out bacteria (only cysts). So you need to use pills or aqua mira to kill the smaller cooties (bacteria and viruses). The great thing about the FP is that it has a carbon element inside, which totally removes any chlorine taste from the pills/AM.

Kevin, go to Home Depot or Lowes and in the plumbing section you can get clear tubing for a fraction of the cost or the platy kit. And you can get whatever length you want.

Also the Platy Clearwater uses a very short tube from the dirty bottle and the long on to the clean. I find this to be backwards and doesn't help build good Hydrostatic head pressure.

I'm with Gary on the length from the dirty bag- anything more than 4 ft is too much hose and a hassle to manage. Remember you have 2, 12 inch bags (dirty/clean) and a filter and the clean tubing that are part of the equation.

Bob, buy yourself 10 ft of tubing at the local hardware store and play with it at home to get the desired/optimum results you want.

Granted my setup is with the sawyer squeeze with adapters and not the mini, but I put my filter inline on a platypus hoser bag that holds the dirty water, and only mounted the filter a few inches at most from the bags outlet. I disconnect the output hydration tube from the filter when I want to use the setup as a gravity filter and simply attach a smart water bottle flip cap directly to the filter output for my on/off. So in all I use 3" of tubing in gravity mode and have had great output speeds with no need to help it along.

Gary, I have never been awfully concerned about bacteria in the water. In the Sierra Nevada and where I operate (never downstream from pastureland), it has generally been Giardia to watch out for. I've never personally gotten sick from the water that came through any of the filter brands, but others who got water at the same place without any filter have gotten sick, so I am likely to keep up my practices. Currently some tubing from a Gravityworks kit is what I am using, but the vinyl hose seems heavier than what is necessary. I sounds like the general consensus is that 3-4 feet of total hose is right.

–B.G.–

I understand what you're doing, Bob. Yeah, the cysts are really what we want to deal with here. Where I tend to hike, there aren't many silly people around, so viruses and bacteria aren't too worrisome. Of course, one never really knows where YNP's bison do their business upstream, so cysts need to be neutralized.

I really liked my Frontier Pro this summer in Yellowstone, when I had to take my water from the Firehole River. I was downstream from a few harmless fumeroles that drained their sulphurous contents into my stream. The carbon element took out the weird taste completely. I didn't grow horns or start twitching, so I "guess" the water was harmless…

Why don't you try to find some silicone tubing after you dial in your desired tube length? It tends to be more expensive, but I really like how soft and pliable it is–nice for coiling into a tight space, like a freezer bag (for storage). The MSR tubing is too stiff for me, and it doesn't hang straight down from the dirty bag like silicone does.

Gary, I can deal with the bulk issues. I just want to cut down on the hose weight.

–B.G.–

"I just want to cut down on the hose weight."

1.2 ounces – 1 liter soda bottle – in Squeeze mode

lighter weight than gravity mode not to mention all the hassle of extra water containers and hoses…

it is such a minor effort to squeeze out a liter of water and takes so little time

oops – sorry – trolling again : )

I will probably use the mini mainly in "squeeze" mode, but I like the fact that it can be used as a gravity filter as well. Now to get it all in hand and start experimenting! :)

Jerry, I got away from squeeze filters several years ago. Way too much hand work, and way too slow.

Besides, the Platypus containers allow me to carry a lot of water when I need to.

–B.G.–

If people want to do gravity fine, I'm not trying to talk anyone into anything, but…

I have one big Platypus for untreated water. Or, if I want to carry all my water in my pack, I have a couple extra 1 liter soda bottles.

Then 1 liter soda bottle that I pour water into.

Then I squeeze water into my pint bottle for drinking. Takes 1 minute. Way less fiddling than setting up gravity mode.

My "minimalist self" thinks there's an extra bottle here, but oh well…

Now, if I wanted to squeeze several liters of water it might take too long and too much hand work. But that's a paradigm from the bad old days when I used my Katahdyn to filter 1 gallon of water.

No need to filter water I'm heating. Only squeeze what I'm going to drink in the near future.

When I squeeze from a clear bottle, any sediments will settle to the bottom. I can hold bottle at an angle and keep the sediments from dumping into the filter. With gravity mode, all sediments go directly into filter.

"With gravity mode, all sediments go directly into filter."

Not in my setup, Jerry. The outlet of the 4-L Platy dirty is located slightly above the bottom corner, and the sediment settles below the outlet. Also, the Frontier Pro has a built in pre-filter that catches all sorts of fine particulates. The Sawyer Mini doesn't, of course.

It sounds to me like you do more fiddling with your technique than I do. But our styles are probably different. I do my water collecting/filtering when I get to camp, and set up all my water needs for the next 24 hours. I expect that you gather water throughout the day while you hike. That's a fiddle for me, and I'd rather carry 1.0-1.5 L. with me and not have to stop. But then, the PNW has more frequent water sources than some parts of the Rockies do.

At end of day I get 1`gallon of water and take it to camp.

I filter 1 pint and drink it while setting up camp.

I filter another pint for drinking over night and brushing teeth.

I filter a third pint in the morning for the next day.

And heat up 4 pints for soup, oatmeal, coffee, tea.

Squeezing a pint of water is such a minor effort it's no big deal. No reason to simplify or "de-fiddle". Having an extra bag and hoses would be a hassle. I just don't get it.

For warm weather I'll filter an extra pint ot two but that doesn't really change things.

But, you're right, different styles lead to different optimum solution.

I’ve had really good luck with Saint-Gobain Tygon PVC tubing, and Kent Systems couplings.

I can’t recall my source for the Kent fittings; I think you have to buy a crapload if you order direct from them. Perhaps some motivated BPLer could set up a group buy or locate a source for smaller quantities….

The Tygon you can find at homebrew stores, etc., but amazon.com is easiest for most people.