The Sawyer Mini filter really made an impact on backpacking the past couple years with its small packed size, and especially its low weight and low price. I got one as a gift and I figured it would make an excellent backup filter. It doesn’t add much weight at all at 2 ounces, and doesn’t take up much volume, so it makes for an excellent backup or emergency water filter.
However, how would it work as your primary filter? Well when Tom and I planned our trip to Cottonwood Lakes Basin in the Eastern Sierra, we decided to give that a try to find out. It’s so light! Tom bought one as well so we both took Sawyer Mini filters out on the trail for our 4 day trip, leaving our other filters behind.
How does it compare to the First Need?
How does it compare filtration-wise? Well, Tom and I have both been using our First Need Deluxe pump filter/purifiers from General Ecology (and now the First Need XL and XLE) for quite a long time and have been pretty happy with them. It’s billed as a purifier and can filter out bacteria, cysts/protozoa like the infamous Giardia and Cryptosporidia and even some viruses which are the smallest living things. I feel pretty darn safe with those specs. They currently list the actual particle retention rating at 0.4 microns.
It turns out the Sawyer Mini boasts a particle retention size of just 0.1 microns! Wow, I’m sold there. Not only that, but Sawyer says it can filter up to 100,000 gallons while the First Need XLE has a capacity of 180 gallons. I assume this doesn’t include backwashing, but First Need’s documentation doesn’t even describe backwashing instructions anymore. That brings me to another point – Sawyer’s hollow fiber filtration method must be way more durable than the First Need’s structured glass matrix cartridge. I know I’ve killed one First Need cartridge by backwashing just a hair too strongly, and judging by comments I’ve seen elsewhere on the web, I’m not the only one. They have updated them to be more backwash friendly in the current XLE version. Backwashing the Sawyer Mini, however, has no such risks. Indeed, you need to power through it to do it properly. Also, freezing is a danger for both, but I’d speculate it’s probably less so for the Sawyer (fibers vs glass).
And back to the weight – the Sawyer is listed as 2 oz but I weighed my Sawyer Mini, 64oz bag, 16oz bag, and the included straw at 5.4 oz. The First Need XLE weighs in at 16 oz listed weight and mine weighs 18 oz when wet. Big difference.
The Filtering Method
This is a slam dunk for the Sawyer by the specs so far. But now we have to consider the filtering method itself. What is a hiker doing when they use these filters to convert stream and lake water to drinking water? This was the practicality question behind our test. We had already tested things at home just to ensure the basic usage, but we needed to try it in the field.
With the First Need, like many pump filters, you stick one end in the water in a good spot, connect the other end to your drinking water container (in the case of the First Need you can attach it to a Nalgene), and then you hand pump steadily to fill your container(s). When you’re finished, you can leave the water source with your drinkable water.
With the Sawyer Mini, your first step is to fill your Sawyer squeeze bag with water. Now, after tests at home in the sink, I found this isn’t the easiest thing to do. You can’t get much water into the collapsed bag, even if you try pulling the sides apart underwater. The 16 oz bag is small enough already, but you’re not getting 16 oz of water in it that way. I got the 64 oz bags so I can fill up more and save time squeezing by not having to switch out bags much, but the 64 oz bag definitely has the same issue. That’s why I brought along a used disposable water bottle (I found one bigger than the usual size for this purpose). You fill your disposable water bottle easily by holding it under, and then you pour that into your Sawyer squeeze bag until you fill it up. It sounds like extra steps, but it’s really no big deal and works great.
At this point, you can hook your squeeze bag up to your filter and begin squeezing out drinking water into your clean container, rolling the bag as you go. A nice thing about this method is that you can fill up your “dirty” water bags and bottles at the stream, and then carry them back to camp or wherever and filter somewhere else.
That’s convenient and nice, but that’s where the fun ends. Squeeze filtering is just plain slow! We noticed it adding significantly to our time in camp (not good for the shortened daylight of late October). It can be a buzzkill when you’re sitting there squeezing and you can’t get on the trail until you’re done squeezing. As we both filtered one morning in preparation for a long day of hiking without any water sources, Tom and I switched filters and compared, but they were both pretty slow. I really wanted to like the Sawyer Mini, but this was tough.
First Need lists their average flow rate at 2 quarts per minute. Yeah there is pumping, but you fill your bottle without too much time and effort really. Pumping never bothered me. Sawyer has a spot in their FAQ about the flow rate, but doesn’t list any actual flow rate. They do say that altitude affects the flow rates (higher elevation makes filtering slower) so it’s possible that affected us.
There are a couple of usage modes that help get around this. You can screw the filter on top of a squeeze bag or a water bottle and drink straight through it, or you can hook it inline to your water bladder and drink through your hose. This means you filter as you drink instead of filtering a bunch at once. I tried this at home with a water bottle and it seemed to work ok. I squeezed the bottle to get a little more flow. I’m not sure I’d like the low flow if using inline with a water bladder. Also, we did not bring along the backwash syringes for our Sawyers. Maybe backwashing more frequently would help.
So now my plan is to keep using the Sawyer Mini for the purpose I had intended originally – as a backup water filter to my First Need. It makes for an outstanding backup with it’s light weight. I’ll also throw it in my day pack when doing longer day hikes. I know there are lots of glowing reviews out there that are happy with the flow though so maybe I’ll keep at it. I’ll note that I didn’t experience any trouble with the bags springing leaks like some others have. I’ll have to be back to post an update if my experience changes.