Sawyer Inline Water Filter and Purifier – Field Tests
I bought a Sawyer inline water purifier about a month ago, hoping it would replace my General Ecology First Need water filter which is about 12 ounces heavier. Both the Sawyer and the First Need are the only EPA approved filters on the market capable of filtering giardia, cryptosporidium, and viruses. The Sawyer (model sp125) weighs 2.9 oz. dry and 6.7 oz. when saturated with water. It has an maximum life time of 3000 gallons with regular back flushing and is designed to be compatible with gravity feed bags and hydration systems. The Sawyer uses a fast flow hollow fiber membrane to filter water. When water is drawn though the membrane, it flows through the sidewalls of fibrous tubes that have holes in them and trap any organisms or impurities greater than 2 microns in size.
I field tested the Sawyer with two different hydration systems using Platypus bladders and MSR Nalgene Wide-mouth Canteens. Unfortunately, the Sawyer did not perform well in either configuration, and I've concluded that you can't suck on a hose hard enough to draw water through a 2 micron filter. You need a pump. Period.
In my first field test, I connected the Sawyer filter about 6 inches from a 96 oz. Nalgene bladder which I filled with unpurified water. In this configuration, dirty water flows from the bladder through the inline filter where is it purified. From there, the clean water travels through about 2 feet of plastic tubing to a hydration system bite valve. Both the filter and the bladder are stored in the backpack and the hose is threaded through the backpack's hydration port. In this configuration, I was able to suck some water through the system but only enough to wet my mouth, not slack my thirst. With each draw on the hose, I also swallowed a lot of air and the entire system was marginal. Gravity filtration in this configuration was also very poor and it took about 10 minutes to filter 2 cups of water. That really sucked because I had to do it at night on top of a cold mountain.
In my second field test, I connected the Sawyer filter about 12 inches from a 3L Platypus bladder and attached the inline purifier outside of the backpack onto a shoulder strap of my pack to test the effect of having a very short tube between the clean end of the filter and my mouth. I tried this variation because I thought that placing the suction closer to the filter might improve the flow of water through it.
I filled a 3L platypus bladder with water in my kitchen and attached the Sawyer to the shoulder strap of my pack. It was a little awkward but not bad. I sucked on the tube at home and the flow was much better, so I packed up the car and drove to my local testing ground for a 9 mile hike. About a half mile into the hike, I took a sip and nothing happened. I couldn't pull any water through the filter. I stripped off the pack and checked to see if I had any kinks in the hose. Nope. So I removed the entire system from my pack and held the bladder over my head to check if I could at least get a gravity feed to work. Nothing again. I checked the filter lock, and that wasn't an issue either. So I broke down the entire system, removed the Sawyer, threw it in a mesh pocket, and continued my hike. When I got home, the Sawyer filter went into my big box of unloved, rejected hiking toys.
My conclusion after trying these two different hose configurations is that you need the pressure that can be generated by a pump-action system to push the water through a 2 micron filter if there is any distance between the water source and the bite valve. This is the reason why a filter like the Aquamira Frontier Pro, despite its ecological deficiencies and 3 micron pore size, works with a soda bottle reservoir. But if you use an inline filter with a hose-based hydration system and refuse to change, I'm convinced that you are SOL and need to stick with pump filters given the current state of the art in inline water purification.
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- sawyer water filter review
- SAWYER WATER FILTER
- sawyer filters
- Sawyer 3-Way Inline Water Filter
- sawyer water purifier
I don’t think the in-line filter is getting a fair shake here. For an in-line, gravity-fed filter to work there must be a column of water above the filter because it is this height that actually provides the force to push the water through the filter. The technique relies on a simple equation from physics and static fluids, p = p0+d*g*L where the pressure at the filter is p, p0 is the pressure at the top of the water column, g is gravity and d is the density of water. The difference in pressure is what produces the force to push the water into the filter. So you can’t have your hose loop around, it must be straight down and they aren’t made for sucking through.
The suggestion of using a pump type filter is irrelevant because as I see it you are trying to make a system that will work while moving but with a pump you will have to stop and manually pump so why not just use a gravity filter like it is intended, hung from a tree or you can even hold it up yourself, if you are going to stop anyways. A pump filter actually runs a little slower than a gravity one, hand pump filters are usually 0.5-1.0 L/min while a gravity filter can filter 1+ L/min. I suspect your tree system was so slow because you didn’t have an air hole in your reservoir. Think about a can of soda, if you turn it upside down it’s very difficult for the liquid to flow out smoothly because it is creating a vacuum behind the fluid, but if you puncture the other side of the can it can “breath.” Every time you got a burst of air in your system it was because the reservoir was trying to equalize the pressure in the bag. Providing an air hole will probably solve the problem but it may still be too difficult to suck through.
I’d agree with you if the Sawyer were marketed as just a gravity filter, but it’s not. It’s intended to be used as an inline filter in a bite and suck hoser system, and for that it fails miserably.
I’ve set up the Sawyer Inline water filter as a gravity fed filter connected directly under a 3L platypus Hoser (2 inches of tubing). I then connected the hose to a platypus collapsible bottle by replacing the bite valve on the 3-1/2 foot tube with a filter link connection to the other bottle. With the dirty water platypus hooked on a tree branch and the clean water bag on the ground I get at least 1L per minute filtration rate. I’m really happy with my 8 oz clean water solution. It really beats pumping. I suspect most of your issue is related to the effect of the bite valve. My filter came with a water bottle basically to use as a straw. No bite valve. Try again without the bite valve. It won’t work as you planned but you may find you pull it out of your unloved toy drawer.
I haven’t tried a gravity setup with a Camelback valve, and I probably should. The MSR bite valve I used is crap. No doubt about that. Of course, I think Platypus now has a gravity system that is even lighter than the Sawyer, but for the sake of completeness, I should try it again and write up the results.
Problem here is that I don’t want a gravity system at all. That was only a last ditch test to see if the Sawyer would work in ANY configuration after failing to work in the configuration that I was told would work – which is a direct bite and suck from a dirty bag through the sawyer and into my mouth. I did test that with a camelback bite valve and it didn’t work. See picture above.
I think you might have a defective unit, or, it may be clogged. I’ve got a Sawyer inline filter and have used it extensively without issue. Sure, there is an increase in required suction, but I’ve found that it isn’t that much more than having no filter at all. Of everyone that has tried it, none have mentioned it was harder to draw fluids, whether they knew the filter was there or not.
Ok and I can find just as many people who’ve shared my experience. Plus, I recently had the same experience with a gravity filter setup using the Aquamira Frontier Pro. I think the bottom line for me is not to trust a gravity system on a multi-day trip. I’ve been burned doing this and it won’t happen again…for a few years, at least. I want a system that works quickly 99.9% of the time, and that’s my First Need Pump Purifier.
My Sawyer Gravity System(Ripstop nylon WaterBag to MSR Dromlite works great). However, the filter is not gaper/flatlander proof. Can’t let it freeze and needs to be primed.
Is your sawyer filter backwards or was it? I own 3 of these filters and have never had an issue running it inline with any brand of hydration system. I liken the force required to drink on par with drinking a milkshake through a straw- not much more than with no filter.
I first must ask you which filter were you using, the inline filter or the inline purifier? It might be very hard to drink in an inline fashion through the sawyer inline purifier. The inline purifier is way overkill for backcountry America use (I’m guessing that’s where you are from your pictures).
The inline microfilter has a pore size of .2 microns absolute, and sawyer’s site says that it’s something on the order of .1 micron. You stated that the filter has a pore size of 2 microns, just be aware that it’s 10 times less than that. Still my previous assertions stand about the drinking force needed. I even use the flow through system for very long days on the mountain bike, and I’m able to sip enough water in a quick enough time while working hard to not be out of breath.
I was using the inline purifier. For areas with clean water free of toxic chemicals and fertizilers, I am willing to use a filter. I prefer using a Frontier Pro in those cases because it is so easy to attach to a used soda bottle or platypus bladder.
I have heard that the Sawyer purifier needs to be primed before it can be used. Priming requires faucet pressure to work. Manually forcing water through the purifier doesnt work. Once it is stored dry it needs to be primed again, meaning it needs to be packed ‘wet’ into the field.
I used a Sawyer inline for my entire Long Trail thru hike last summer with great results. My father used a Steripen and got beaver fever, my buddy used aquamira and always took twice as long to water up as I did, to say nothing of the 30 minutes he always had to wait before drinking. Occasionally the Sawyer would get slow, particularly if I let air into the system, but with careful use it is a really great solution that kept me healthy.
As another commenter mentioned, the filter pore size is 0.2 microns (two-tenths of a micron). 2 microns is too big to filter out viruses, and if you don’t understand that you are probably out of your expertise trying to evaluate a water filter.
Gents – I think we need to be more specific about model numbers here. Sawyer makes a lot of purifiers and filters. They’re not all the same\. That said, pore size is not an absolute indicator of effectiveness. REI doesn’t list pore size on their filter guides for this specifc reason – there’s of marketing bull**it out there. Also, giardia, which is commonly referred to as beaver fever is not a virus.
I didn’t mean to suggest in my post that 0.2 microns will remove viruses any more than 2 micron pores. It won’t. You need iodine or UV light or something like that to kill viruses. But the smaller the holes, the harder it will be to get water through it.
Tom – didn’t think you did. I just super picky on this topic. Must be because I’m a pisces. Purifiers remove viruses, but must be certified by an EPA approved lab to be called a purifier and not a filter. You can also kill them with chlorine dioxide and UV light, but water temperature and turbidity can effect thier effectiveness and required exposure time. Of course, not sterilizing your hands after you treat water can negate everything.
W.H.O. has some papers on water filtration. For example, search katadyn on their page. Regards.
I sense some confusion here. Since a Sawyer just came in the mail and I’ve been tinkering with it for a few days, maybe this will make it worse.
1. They make a great filter, and some not-so-great filters. When I saw the 0.02 micron type, I had to have it. Never needs to be replaced and will get me out of chemically treating my trail water. They do a bad job of explaining the differences between their models. Or even making boxes that accurately show what you get.
2. Despite having great filters, sometimes Sawyer builds those filters into non-functional systems. Amateur astronomers quickly learn that an expensive telescope needs an expensive mount. Sawyer has not learned this lesson.
Model SP-194 has the 4 liter bladders, which I knew would need some tinkering if not complete replacement. Recently they changed the product, switching from valved and hose-tapped caps to plain caps. I called to explain that, even in a base camp, this renders the clean water bladder practically useless. But they don’t answer the phones *ever*. As if that pathetic level of customer non-service could stop me. An old cap is on the way.
3. The vast wetted surface in the design of these filters is troublesome for occasional use. That may have defeated your tests, EL. Although some water may initially dribble through after priming, I believe these filters need many gallons of use and some time to reach their peak flow performance. Mine keeps getting better. Currently it produces a pint in 3 minutes with 4 feet of head. With effort, I can suck plenty of water through the filter. But I’m usually gasping for air on the trail, so drinking through a tube is no fun for me.
4. The bladders that come with model SP-194 are clunky, opaque, too large; but sturdy. More of a base camp design, and better for 2 backpackers. Likely I’ll replace the reservoirs to save a few ounces. 2L (dirty) + 2L (clean) would allow me to carry 8 pounds of water, which is plenty for any foreseeable circumstance. Somebody mentioned a water bag for the dirty reservoir. That has some appeal.
5. I am confident this filter will protect me from all diseases in highland water sources without further treatment. Of course there is no absolute certainty in this, but I’m far, far more likely to catch a bug from sleeping in a shelter with close proximity to other hikers.
6. I don’t think there is anything a portable filter can do about chemical contamination. Reverse Osmosis membranes have pore sizes measured in nanometers, and need sustained mechanical power to produce a trickle of lab-quality water.
You like to stir it up (I like people like that). Check out the first need XL. They claim to be able to filter out chemical contaminants like fertilizer and heavy metals. I’ve used their purifier for years, but going light in scotland with chlorine dioxide tabs. The locals claim that you can drink water right from the burns, but beavers are now repopulating England and I’m not up for a case of Giardia if I can avoid it by carry two oz. of tablets.
“You like to stir it up ….”
1. I’m certain that I have no idea what you mean by that.
“… going light in scotland with chlorine dioxide tabs.”
2. Clearly that is an overwhelmingly appropriate solution for your trip. It would also work for my trip, but it is more reasonable to give myself the luxury of non-chorinated water on the LT than in Europe.
“… chemical contaminants like fertilizer and heavy metals.”
3. I haven’t seen the manufacturer make those claims. They do claim a filter pore size of 0.1 micrometer = 100 nanometers. Fertilizer particles (nitrate, phosphate, sulphate ions) and metal atoms (lead, arsenic, chromium, nickel) all have diameters < 1nm. Even benzene is only half a nanometer.
4. The First Need XL looks like a great product, and is perfectly suited for hikers who need active solutions. The passivity of gravity trickle systems will simply drive many people nuts.
5. Agriculture is always the biggest threat to water quality, so higher elevation is a safety factor. In the highlands of the English-speaking world, you have to go well out of your way to find a waterborne threat smaller than feeks. So it's important for certain people, who may have worked as a chemist and microbiologist for the Vermont Dept. of Health and Dept. of Water Resources, to stop obsessing over this topic.
I bought the sawyer inline purifier back in sept of 2009 and have only used it 4 times. 1 time in the field and 3 times at home with tap water. I sent the filter to sawyer and spoke to john smith about how it is taking 45 minutes to filter 4liters. He told me to send it in and he would fix the the problem and if not send me a new filter. He sent the filter back saying everything worked fine so I tried filtering tap water once again. It still took 45 minutes to filter 4L. so I emailed him back and he said there is nothing wrong with my filter and that there is nothing else that sawyer can do for me. also would like to mention that on their website it says that it will filter 4L in under 6 minutes and when I spoke to John Smith he said that it actually takes 15 minutes. so I guess the company does a little bit of false advertising. Also the clean bag leaks..Hmmm..I would personally stay clear of this company as seeing that they do not stand behind their products.
I bought the dip N’ sip filter from Wal-mart awhile back, it’s a water bottle with the .1 filter inside and some tubing. This purchase was for use as a gravity filter system as it cost $40 for a water bottle and filter compared to $40 for just the filter at REI. This thing works great, real fast fills my 2L Platy Hoser in a few minutes. I think the issue most of you are seeing is that you are using the purifier and not the filter. The purifier (.02 micron) has holes way too small to be of any use in the backcountry of the US. We don’t have viruses in our stream and lakes so .02 is overkill. Stick with the .1 and you will see good flow rates, and by the way I use the Platy bite valve on mine for ‘on-off’ functionality in camp and the flow rate is still great.
I have two Sawyer squeeze and sip bottles I bought at Wal-Mart some time ago. I had some problems with one (the threads to secure the cap were not moulded correctly and when squeezed with any force at all the cap popped off). It also leaked around the threads with just normal pressure.
Another problem was attempting to suck water through with the provided pre-filter. Maybe I’m just a feeble old man but my face turned blue just trying to get a trickle. I looked like Maynard Ferguson hitting a high C.
I tried to contact them at their “feedback” address and never heard anything from anyone. Tried to call and got a round robin menu that got me nowhere; couldn’t talk to anyone. I can get a better response from the IRS than I got from them. They’ve earned my “no confidence” vote.
In response to Helen W’s post, “Model SP-194 has the 4 liter bladders, which I knew would need some tinkering if not complete replacement. Recently they changed the product, switching from valved and hose-tapped caps to plain caps. I called to explain that, even in a base camp, this renders the clean water bladder practically useless. But they don’t answer the phones *ever*. As if that pathetic level of customer non-service could stop me. An old cap is on the way.”
It seems as though they now sell the old version or the new version on http://www.moontrail.com/sawyer-sp194.php .
Im seriously looking into buying this.
not “or the old version”, they sell both versions.
Want my advice? Assemble your own gravity system with 2 platypus bladders and a seychelle purifier that comes with quick connect drinking tube adapters. You’ll save about 100 bucks. See this post: http://sectionhiker.com/aquaguard-eliminator-inline-purifier/. You can now buy the inline filter in the states direct from the manufacturer at http://store.seychelle.com/Products-In_Line_Filter.html for $30. I just bought a bunch of new purifiers from them myself. Sawyer is a terrible company. Let natural selection kill them off. I tried calling their customer service number once too. Frack’em.
Hey Earlylite, about a week ago I came across your posts about Aquaguard Eliminator. After many unsuccessful attempts at importing from the UK I spoke to Giles of drinksafe UK and he told me that he actually imports the product from Seychelle and repackages it for sale in the UK. Anyway, I got my $30 unit from Seychelle a few days ago. I have two questions for you: (1) have you experienced any leaks from the filter unit itself? On the black filter itself where it looks as though the two pieces of the case meet each other(there is a little indentation that travels around the circumference of the unit indicating a connection point) water is seeping out of this area. It definitely is not coming from the connectors or tubes. I dried everything and checked it several different times but each time water seeps from that tiny slot that goes around the circumference of the unit. (2) At first the taste of the purified water was quite salty (I was warned this would be the case). I have run about 9 litres though the filter but it still has a “taste” sort of chlorine in nature. Do you have this issue with the Seychelee or if not how many liters does it take to flush it so the water tastes crystal clean? Thanks for your help!!!
Been a year – I probably flushed it with about 2 gallons. No problems after that.
I never had any leaking around the housing. If you don’t want to return it, I’m sure sealing it with superglue would work.
How come Giles never told me I could get it cheaper in the US?!
Thanks for your response, I am glad that I found a thread you are active on. I really appreciate all the information that you post to this site!
Okay, so sounds like you are indicating that you also experienced the chemical taste, but it was not long before it dissapated, correct?
Hummm, were you in direct communication with Giles? I think I just wore him down. He has been on holiday here in the US and he called me because once he hit US soil he was unable to send email. Before he left the UK he said he would bring one with him but he forgot. I think he felt badly since I am in a time crunch (thru hiking the John Muir Trail beginning August 2). Anyway it all worked out in my favor. I’m glad that he was forthcoming about it.
I thought of another question Earlylite. Seychelle does not include the prefilter unlike the UK version. Giles told me to go buy some aquarium pump filter fiber. What I don’t quite know is how much to use and how do it position it in the inlet end of the filter? Can you help? Thanks again!
I never experienced the salty taste. I’m not sure why you would either. Have you tried putting bottled water through it. Maybe you are tasting something in your local municipal supply that you didn’t know was there.
My UK inline does not have a pre-filter (don’t know what you’re talking about.) If that’s an issue for you pour your water through a paper coffee filter before you put it into your dirty bottle/reservoir. Frankly, I wouldn’t put anything in the input hole of the filter. You might never get it out, and permanently muck up the flow.
There are problems with your test setups which are visible in your pictures. In the first picture of your gravity setup, it appears that there appears to be a kink in the hose between the bladder and the filter.
In the second picture you can see that in the relatively long hose between your water bladder and the filter, there is air trapped in the tube. Air in the line is the enemy of this filter because, for whatever reason, air will not pass through the filter.
I have used the 0.1 micron (non-virus) filter with excellent results by simply placing the filter unit directly into water and sucking water out through a tube. There is some resistance, but it is easy to drink as much as one wishes.
Obviously, you are testing the .02 micron virus filter which has a flow rate that is ~1/5 of the filter that I tested according to the flow rate numbers published by sawyer.
0.1 micron flow rate data:
http://www.sawyerproducts.com/msds/What%20can%20I%20expect%20as%20a%20flow%20rate%20from%20my%20filter.pdf
0.02 micron flow rate data:
http://www.sawyerproducts.com/msds/What%20can%20I%20expect%20as%20a%20flow%20rate%20from%20my%20Viral%20purifier.pdf
FYI, in my case, I am doing kayaking, so the filter is located on the bottom of the boat in front of my feet, and I can easily sip water through a ~5 ft hose. I have “field tested” this setup multiple times during training and successfully used the setup during a 100 mile race to supplement the water I received from the bank crew (so I didn’t have to carry as much water in the boat between check points). (This is being done in warm weather, so perhaps higher temperatures make for faster flow as well.)
It should also be pointed out that in a gravity setup, you want a long (vertical) hose between the water source and the filter so as to build up as much pressure onto the filter as possible.
However, when you are sucking water through the filter by mouth, you ideally want the filter immersed in water to avoid air getting trapped between the water source and the filter.
Tommy – thanks for the comments. Just wanted to set the record straight on one point. Micron size is not necessarily correlated with flow rate or even filtering effectiveness. Instead the degree of tortuosity is usually the main determinant – the degree of the internal twists and turns of the filter/purifier pores. Ignore the XX marketing department that wants you to think otherwise.