Thoughts on the Sawyer mini

Eric,

I have been using a Sawyer filter since 2008-2009?

First with original black filter and now with the mini.

It has been the only method of water treatment that I have been using on my backpacking trips.

The first time I used it was when a “group” pump filter failed and I had to filter liters of green water through the Sawyer “black” filter.

The water came out with a greenish color to it, but the four of us had no choice and drank liters of the stuff for the that night and part of the following day….an aborted trip as my wife, at the time, had fallen and hurt her ankle.

Anyway, still alive and never been ill.

The Sawyer is a solid technology, just wish that there was a version of it that incorporated active charcoal for water sources that don’t taste so good. (It would have to be a cartridge that could be replaced).

Not much of an issue where I am backpacking….the Sierras, but would be nice.

I have not had any issues with a noticeable decrease of the rate of flow with mine over the years.

I have read that someone suggested running vinegar??? through the Sawyer to restore the rate of flow after a long period of dry storage???

I might be remembering that wrong, but just a recollection.

Tony

Tony,

I have the same recollection as well.  I think I recall seeing this on Sawyer’s website.  Lately, I was browsing the website and was unable to find any of their old instructions about cleaning / sanitizing the filter.  They seem to have disappeared.  Can anyone link me to them?

By the way, you mentioned using soap.  I have written down in my notes that Sawyer says not to use soap.  I think they recommended bleach alone.  I’m curious if your water has ever tasted soapy?

Regarding filtration testing: it seems it should be fairly easy to test.  Simply take a marker that is > 0.1 micron and run it through the filter.  I’m not sure such a marker would be visible to the naked eye, but certainly a compound microscope should tell you whether it made it through.  Perhaps use flourescent dye technology?  I’m curious to test this out…

Soaps are bad as they are surfactants and change the wetting properties.  Vinegar would probably be ok as it would break up hard water deposits (calcium).  If I used vinegar, I would probably backflush with isopropyl alcohol and then water again.  Markers are near impossible as the best way to measure sub micron particles is with laser diffraction.  Another issue is quality control of the particle size.  It would be nearly impossible to manufacture a particle in a tight range ( like 1-10 micron).  I spent 3 years at a company designing scientific particle size characterization equipment.  My 2 cents

does anyone know of a marker that is > 0.1 micron?  does such a thing exist?

another idea – https://en.wikipedia.org/wiki/Capillary_flow_porometry

they measure filter pore size by wetting the filter, then apply inert gas on one side and gradually increase pressure.  From the pressure they start seeing bubbles, they can infer what the pore size is.

maybe just apply water on the filter like normal, gradually increase pressure, the pressure when water starts flowing would indicate pore size.

Or apply a pressure (supply bag at some specific height above the filter) and measure flow rate.  If the flow is too large then there must be a tear in one of the filter tubes.  Fewer pores with bigger diameter would provide the same flow as more pores with smaller diameter, so this wouldn’t be real accurate. If you did this for a filter occasionally you could maybe detect that after a trip when you thought it might have frozen it was damaged.

You guys are delving off the deep end with this.

Most filters are “nominal” and do not have a fixed pore size. A bubble test can be done on an absolute filter, and if done correctly will provide a means to validate the filter. I’ve never heard of validating nominal filters, maybe it exists, but in any situation that was critical enough to validate a filter, it was only ever an absolute filter in my experience (which is not all encompassing by any means).

Talking about putting markers and what not through filters… they’d have to be some sort of lab reference and I think the cost of something as such (if it exists) would far outweigh a new Sawyer filter.

Not to mention that end users are probably as likely to screw up a test as they are to get it right… at best. Would it be nice to validate our backpacking filters? Yes. Practical? No.

I think a microscope would be the easiest way to do this… even then though, user error might lead to a bad conclusion.

I’ll go ahead and take responsibility for leading everyone down the rabbit hole on this one. Clearly my comment on testing the first need cannot be applied to a different technology. If there were a way to test a Sawyer filter, Sawyer would likely publicize it.

I think it would make a cool project though if there’s a BPL’er with a compound scope, some free time, and enough trust that we could send our Sawyers to them and have them run some pond water through them, then provide some qualitative results. I know a few guys who work at a local lab, I might ask them to check my three filters out on their lunch break :)

I happen to be enrolled in a microbiology course at the moment.  I’m wondering if my instructor would give me permission to whip up a batch of E coli and then introduce into someone’s filter.  I could then prepare a slide to see if it made it through.  Any volunteers? :)

i sent an email to sawyer not too long ago and asked if a mini dropped from around waist height could damage the filter ….

never got a reply

while we should always baby UL gear, that isnt always possible or practical ….

;)

David,

Not sure why I started using a little bit of soap…talking about just a drop or two in a liter.

No soapy taste, but I did back flush a lot of water thought the filter to make sure that there was no bleach or soapy taste.

Given what I have read from others, I will skip the soap and stick with bleach.

Where I live in the Bay Area, the water is already naturally soft, so vinegar is probably not something that I would need to use.

As for testing the filter…I really see no point.

Going on faith that we are not being lied to by the manufacture.

If I suspected that the filter has frozen, time to toss it out.

The mini’s can be found as cheap at $15 to $20.

Small money in the great scheme of things.

But I do agree with the comment that you just have to baby the gear a little bit to make sure that you don’t damage the filter.

In colder weather, I sleep with my filter wrapped in a light wash cloth and tucked into my rain gear/extra clothing in my bivy to limit the possibility of freezing.

Tony

I am happy to be led down a rabbit hole : )

Really it’s only freezing I’m worried about, otherwise happy to trust manufacturer and other testing

No matter what you do, occasionally it would be possible for it to freeze

Another thing is I don’t think the filter is that sensitive to freezing.

You can shake out the water from outside the tubes.  If you didn’t, the case would crack and the filter would be useless.

The tubes are designed to expand when backflushing so if the water inside them froze it wouldn’t matter.  You can’t easily shake this water out.  If you did, the pores might crust up, better to leave them wet.

It would be nice to test this.

Sawyer doesn’t really care.  They just say not to let it freeze.  They have happy customers so no need to worry about it.  If they said the filter could be frozen if you shake the water outside the tubes, some people wouldn’t do this and then complain their filter broke.  Easier just to say don’t freeze filter.

Hi folks,

Well, I’m sorry I’m a bit off your discussion, back to gravity filter on-the-go. There was a comment that it would take more weight. So no, it would not. You fill in the same amount of water. Say you fill 1L when you get to a creek? so you’re filling same 1L. then hang dirty soft bottle upside down on the side of your pack and another, clean, bottle in the side pocket. Not an issue. You won’t wait at all…

My $0.02

I suppose there’s nothing inherently wrong with filtering on the go.  However, again I typically drink as much water as I possibly can before hiking on.  Even if I only drank 0.5 L, I’m saving over a 1 lb of water carried.  It’s also nice to sit down and take a break while my water filters.

My backpacking buddy Patman uses a Sawyer filter, I guess the squeeze, and mirrors Jerry Adams comment about “Don’t let it freeze.”  Patman says it’s ruined if it freezes.  Pointless then to take it on a winter trip.

Jacob D says “Freezing probably has the highest potential due to user error” but I just don’t see this problem as user error, in the least.  It would be impossible to keep a water filter from freezing at 5F to 20F on a 14 day trip.  You’d have to stay in a warm motel room for two weeks just to keep your filter alive, or strap it permanently to your perineum.

I let my old PUR Hiker filter cartridge freeze solid and when I need water place it inside my down parka for 30 minutes and it’s ready to go.  Does repeat freezing and thawing kill my PUR?  Apparently not as I’ve been drinking some pretty foul water with it for many months.

Here’s my buddy Patman using his Sawyer filter at the spring on top of Big Frog Mt in Tennessee (in the Big Frog wilderness).

Other than freezing, the biggest drawback I see with the Sawyer system is its inability to suck up water from a tiny source as other filters can do.

Here’s an example of a tiny seep source with a leaf placed in clear water to not stir up the mud and silt and then sucking up this clear water thru the filter.  A Sawyer would have a hard time with this unless you took several steps to keep silt out.

You just keep it in an inner pocket when you’re hiking, and your sleeping bag when you’re sleeping, and it doesn’t freeze.  You don’t have to keep it particularly warm.  I had no problem keeping mine from freezing though I have discovered that hydration bladder hoses freeze surprisingly rapidly in the winter (didn’t hurt the hose, but cracked one of my quick disconnect fittings, so now I carry a spare just in case I need to do a field repair).

I really don’t like that stock bag that Patman is using and replaced mine before ever using it.  I use a Platypus dirty water bag with a big zipper opening on the top.  I can use a cup to retrieve water from a shallow source if need be and easily pour it into the large opening.  If a little silt gets in it’s no big deal – since I filter directly into a clean Platy soft bottle or bladder, the whole system is closed and leakproof – I can simply squeeze the clean water bag a little to backflush the filter.

My entire plumbing kit (Sawyer 3-way filter):

Down to 20 F as long as the ground isn’t frozen, I just shake the water out that I can, then put it in zip top bag, then put it on ground, and cover with stuff like pack or grass.  If the water drops on the inside of the zip top bag start freezing, you’re still okay but just barely.

ill ask the same question with my fellow BPLers that sawyer refused to answer  …

what if one drops it from waist height … do you throw out the filter even if theres no visible damage?

;)

It’s not a fragile filter design, so I wouldn’t worry about it.

Well, I finally got around to doing a video on the Sawyer mini vs.the all-black nondescript filter. Watch the video to find out which is the winner:

https://www.youtube.com/watch?v=8X8YkD5Xvp0

Spoiler alert: The all-black filter wins hands down. It filtered 1.5 L of tap water in just over 1.5 min. The Mini…well let’s say that it’s being retired.

I’d like to stop by the hardware store to buy some tubing for a gravity setup. Is there a particular diameter to look for and is there an inexpensive way to attach thin tubing to a platypus?

I ordered some thinner tubing from US Plastics to save weight.  I ordered 1/4″ ID tubing with a 1/32″ wall.  I believe that Platy tubing is 1/16″ wall.  The problem is that it’s a bit too flexible.  I’m thinking I may just go back to Platy tubing after all. I just found some tubing a second ago on US Plastic’s website that seems the be the same spec as the Platy tubing:

http://www.usplastic.com/catalog/item.aspx?sku=59041&gclid=CPDJhOXZscsCFQmQaQodhqEBLg

As far as connecting the tubing to a platypus, it’s difficult to do unless you order the dirty bag from their CleanStream or GravityWorks kit, along with a male disconnect. However, Kurt here has turned me on to the fact that these parts can be purchased from US Plastics as well.  There’s another thread on this here with links.

I’m currently using an alcohol nozzle that you screw onto a Platypus that I purchased from BPL around 2008-9.  I think I will try to set up a quick disconnect like Kurt has.  He posted about this in another thread.

@dgposton – did you have air bubbles like you did with the mini filling up the hose when you attached it to the black filter?

I did an experiment the other day where I hooked up all three of my filters in series and squeezed water through all of them.  It seemed to me that air bubbles would work their way through the Squeeze and 3-way pretty quickly, but not the mini, which bubbled only a tiny bit very slowly and continuously – I never did manage to get it clear.  Air bubbles are definitely a bigger problem for the mini.

The flow rate you got with the black fliter in gravity mode is impressive, considering the light weight of the filter.

Mini has its place on a weekend trip where a reduction in flow is minimal, and using a few tablets (or gasp, some diarrhea) isn’t a big deal.

On a longer hike, 4 days out, I carry the fullsize.
If I ever hike in a desert environment, where it is routine to collect 6-8 liters at each source, I will have the fullsize.

The flow rate is good initially, after a few 10’s of liters it becomes un-flush-able.  I flushed every 5 days and used a bandanna when there was obvious particulates.

I look at it as consumer grade vs pro grade.  For the vast majority of hikers taking a trip or two a year (at best) its fine.  For those of us who spend more time out than in, worth its weight to carry the best.

I’m probably in the minority thinking that sexiness comes from the simplest package ;-) ….but, if anyone’s interested in my gravity method I posted a pic of on page 2 of this thread, here she is:

The cord threaded through the bag’s hole: One end has a mitten hook, the other end a mini cord lock. I wrap the mitten hook around a tree/bush/ect and hook it on the cord…like in the pic. I then use the cord lock to adjust the height of the now hanging bag. Finally, I place my water bottle under the “Mini”, walk away, and let nature do the rest. I still have my original Sawyer bag. Still holds water.

Minus the weight of the Mini, this 32 oz Sawyer bag set up as shown weighs .78 oz. Not fancy. Not heavy. Not many parts. But simple and Sexy!  ….well, in my eyes……

David,

so if I am getting all this right, the “generic” black water bottle filter has the same specs as the squeeze, and flows like the squeeze, but weighs closer to the mini?

Gonna be hard to buy another squeeze :). Of course the way it’s performing I may never have to.