GEAR REVIEW: The 1.3 Ounce Sawyer Mini is the Lightest Water Filter Available

By Will Rietveld

Water treatment is always a hot topic among lightweight backpackers. We ditched the heavy pump style filters long ago, so they are totally out of the picture. Now it’s a debate about which is the best lightweight effective water treatment system: Aqua-Mira drops, Aqua-Mira tabs, Ultra Violet, or the Sawyer filters. Other “lightweight” filters on the market require expensive replacement cartridges, so I omit them.

It seems there is no “perfect” lightweight water treatment method currently available – they all have some drawbacks – so it’s a personal choice based on how one weighs the following factors: effectiveness, weight, convenience, wait time, taste, and cost.

My personal experience is probably typical: Aqua-Mira is the lightest system, but I got tired of the mixing and wait time, and the tabs are expensive; the Sawyer Squeeze Water Filter (2.4 ounces) is lightweight, but I got tired of sucking to get my water – too much sucking and not enough drinking; the rechargeable SteriPen Freedom (2.65 ounces) is also very lightweight, but it requires a wide-mouth bottle for treatment and a full charge may not last through a trip. The SteriPen stopped working on a recent trip, which makes me less willing to rely on an electronic device for water treatment.

The new Sawyer Mini water filter weighs just 1.3 ounces (without the cap and drink tube), and can be used a variety of ways. It comes with a heavy-duty syringe (for backflushing), a drink tube (for drinking directly from a stream or lake), and a 16 ounce flask for $24.95).

Enter the Sawyer Mini (in September 2013), which at 1.3 ounces (without cap and drink tube) is the lightest water filter currently available. That’s roughly the same weight as using the Aqua-Mira drops in small dropper bottles! The beauty of the Mini is it filters to 0.1 micron (the same as the best pump filters) and it doesn’t use expensive replaceable cartridges. It comes with a heavy-duty syringe for backflushing, and it can be backflushed indefinitely; Sawyer guarantees it for 100,000 gallons.

Backflushing is the key, and I can’t emphasize that enough. I used the Sawyer Squeeze Water Filter on many, many trips over a two year period and found that backflushing is essential after every trip, otherwise it is progressively harder to suck/squeeze water through the filter. If you go on an extended trip, take the syringe with you.

Another thing I learned is the filter can become “plugged” if it sits around for an extended period. After using it all summer (and backflushing it after every use, including at the end of the summer), the filter was unused over the winter. The first trip I used it the next summer it was very difficult to suck or push water through it, which was a pain since I was dependent on it. When I got home I soaked it in water overnight and backflushed it bigtime and was able to restore it to its “normal” performance, which I described earlier is a little too much sucking and not enough drinking.

Back to the new Mini. In my initial tests I found the flow rate to be much better than the Squeeze filter, but of course that can decline over time. For that reason, this will need to be an ongoing review of the Mini; I will add to this blog as I use it more over time.

My favorite way to use the Mini is screwed onto a beverage bottle. This is the same application as Sawyer’s Squeeze Water Filtration System. You drink by squeezing the bottle and sucking at the same time. The bottle is easy to fill from a stream or lake and is easy to insert into a side pocket of my pack.

 Another strong point of the Mini is its versatility; it can be used in a number of different ways: screwed on a beverage bottle, screwed on a Sawyer flask (but not a Platypus flask), used as an inline filter in a hydration system, in a gravity filtration system in camp, and drinking directly from a stream or lake.

My favorite system is the Mini screwed onto a 1-liter beverage bottle. The bottle is free and very lightweight, can be filled from a minimally flowing water source, and is easily inserted/withdrawn into/from a pack side pocket. In contrast, a flask is very difficult to fill from a stream or lake and does not carry well in a side pocket, but it works well for camp water.

One final point in this installment: it’s very important to protect a Sawyer filter from freezing. The filter uses a microtubule system for filtration, similar to that used for dialysis, which can be damaged by freezing, resulting in an impaired ability to safely filter water.

Stay tuned for future reports on the Mini water filter after I use it more in the field over time.

Addendum Nocember 17, 2013
I recently took the Mini on a 5-day backpacking trip in Utah's canyonlands country, where the water is often a bit cloudy. The Mini mounted on a one liter beverage bottle performed flawlessly, maintaining a good flow rate. I prefer to drink directly through the filter by simultaneously squeezing the bottle and sucking, but pre-filtering the water into another container is almost as fast and you can gulp the water.

One caveat with using the Mini mounted on a beverage bottle is the bottle flattens as shown, so you need to unscrew the filter one-half turn to expand the bottle so you can drink from it again. That step is unnecessary if you pre-filter water into another container or use the filter inline in a hydration system