I don’t believe the million gallon/10 year durability claimed by the company is anything more than presumptuous, unscientific, salesmanship hype. This concept is a fantastic idea, and the warranty is great if Sawyer actually follows through on it (how do differentiate between premature clogging from poor maintenance and a defective unit?), but I hardly see the durability claim as yet demonstrable. It would take almost 5 years of continuous back flushing to prove such a claim. I don’t think the filter has even been around that long, much less 10 years. Although, I do see it is being tested in the field by many tens of thousands of their customers as Sawyer says in their materials online. Mostly what I’ve heard in complaint from some of these “testers” is the original bags were breaking and the filter significantly loses flow rate over time.

Sawyer has insisted that all the problems people have been having is due to not back flushing the filter well enough. If they had an effective 10-20 micron nylon mesh pre-filter (which Sawyer customer service has asserted is “unnecessary” and therefore “immoral” to sell with the filter, NONE of the problems their customers have been having would probably have been encountered in the first place, regardless of who is at fault. It boggles my mind why they wouldn’t unburden themselves of this crowd of infuriated complainers and just sell a $5,1/2 oz or less accessory inline pre-filter.

If my memory serves me well, most sediment is between 50-100 microns, silt down to about 25 microns and iron (most foggy on this one) is above 10 microns. Sediment under 1000 microns that can get in the tubules can be rough at a microscopic level. The force of backwashing can theoretically force it against the tubules, scoring it and changing wall smoothness factor (e/D) which can increase friction of flow and reduce flow rate, especially if the turbulence is high enough. A rougher wall can also increase the possibility of debris getting trapped. Filtering relatively clean water should reduce the need for back flushing and make less likely any of the problems associated with improper customer maintenance. Yet Sawyer still maintains “it’s not needed”. I guess they would rather repeat that assertion until their market buries their product in the cemetery of public opinion.

I intend to use my filter as a gravity feed system, so maybe I can permanently install your idea in the adapter at the bag. That way I would never have to remove anything from the filter except the adapter head.

Thanks for your generous response. I appreciate it.

I haven’t had the opportunity to have used this stuff as much as I had hoped since I wrote that article, but let me answer from what I have seen so far:

1: You can’t use a bag instead of a syringe, the pressure is not great enough to backflush out the gunk. Sawyer says inadequate backflushing results in the filter slowly failing over time, or losing the outer ring of filter material to clogging as the course of least resistance is developed over time and improper backflushing. You can by the way find 20 ml irrigation syringes, I’m not sure if those are big enough or pack enough force, but they are a lot smaller than the big 60ml ones. With the hose and adapter, you can get a decent amount of force with a smaller syringe.

2: your idea of using just the cut off top of a pop bottle seems as good as anything I’ve heard to keep the filter in place, except it doesn’t make sense, you want the filter screen out so the water can flow out unimpeded in backflushing, along with its gunk, and you only backflush once a week, so that’s in fact not a very good idea at all in my opinion, the point is to wash it all out, not to trap it behind the pre filter screen. It’s not hard to put in the filter/washer, takes a few seconds, toss it in the filter bag while you backflush to avoid losing those light things, reinsert when done.

3: I have no idea why anyone would use a .1 micron filter without a prefilter, that simply makes no sense to me at all. I don’t have enough trail miles with the filter to report on long term use, but I would always flush it on returning home anyway with the big 60ml syringe, a few times, then clean it out with a light bleach solution for storage. Also, by the way, hard tap water can gather in the tubes over time, so it pays to flush it with purified water now and then too, and I believe warmer water. If I were lucky enough to be able to do a longer hike, with a bounce box, I’d probably just toss the big 60ml syringe in that and use it, then pack it up again. The little 20ml seem to put out enough force however, even the 10ml is ok, but it doesn’t have a long stream, which might not backflush that well. I don’t know how many microns the ace hardware coffee filter it, but it’s going to keep out anything big enough to get stuck in there and start breaking apart over time, for example.

4: I have found no particular change in flow of the filter with a screen in it. Easy to confirm, try it and see.

In terms of backflushing, if you are getting water from fairly clear streams, you should really not need to backflush at all for a week, give or take, unless you are making water for two, then you should. I bring it with me to be on the safe side, but I haven’t needed the syringe yet while actually on the trail. But time will tell.

In terms of the claimed life of the filter, I dont’ believe anyone in the real world will ever achieve that unless they use it perfectly, as directed, backflushing, cleaning, light bleach solution for storage, no hardwater at home, and so on, and even then I doubt it would last for a million gallons, but even if it only lasted for an order of magnitude less, ie, 100,000 gallons, that’s stunning for a filter, mind boggling, amazing. Assuming hot day, at 4 quarts a day, 1 gallon, that’s between 100,000 and 1 million days of use…. And if true viruses etc are expected, one can then after treat the filtered water with regular bleach, which is NOT safe for giardia, despite persistent internet misunderstanding between regular bleach and the stuff in purifying drops, but I believe bleach is fine for sub .1 micron organisms, which most people seem to agree are not real issues in the first world.

Also, removing the washer and pre-filter screen every time you back-flush, then replacing it, is cumbersome, at least that’s what I found when replacing the original washer after I removed it to examine the filter. What if you simply screwed in the cut off business end of a drink bottle to hold the washer down while back flushing? I can’t imagine anything coming from inside the tubules will be greater than the 15-20 microns of the coffee filter and the back-flush water is getting filtered to 0.1 microns, anything that size or smaller should easily pass through the screen. Besides, this would help clear the sediment from the outer side of the coffee filter, wouldn’t it?

Also, I read typical use of this filter (without a pre-filter) results in the eventual PERMANENT halving of the flow rate performance. Have you found that this Ace Hardware coffee filter protects the performance of the Sawyer filter?

Lastly, do you find the Ace Hardware filter when free of debris noticeably reduces the squeeze filter’s flow rate, particularly when used in gravity mode, or is it about the same?

Thank you for this informative article. Looking forward to your reply.

I heard a little bit of talk on backpackinglight.com about the new generation of sawyer bags, that apparently are thicker. I hadn’t heard that they were including an inline adapter, but maybe that was their recent ‘revolution in water filtration’ they advertised, not having any actual revolution beyond their very nice filter tech to promote, so I assume that was it.

So if REI is shipping the new sawyers, good for you, let us know if the bags hold up under reasonable use.

To me, it’s the clean end adapter that is most useful, the other end I don’t need anything for because the filter is only used when I prepare clean water.