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Lightweight Backpacking Water Treatment

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Portable water filtration pumps for hikers are pretty convenient – throw the hose in some water, start pumping into a container, and drink. Low maintenance and fairly reliable. I’ve used the same Katadyn Hiker Pro for years without any problems (and still have it in my box o’ camping supplies). I completely trusted it to filter water from a creek in Scotland that ran right through a cow pasture and I never got sick.

But for those weight-conscious backpackers (conscious about your pack weight, not yourself) they add many unneeded ounces to our pack and we’re left to search for another lightweight backpacking water filter or other treatment option.

If you’re joining the lightweight or ultralight mafia, here are some other options you have for treating water in the backcountry. They’re way cheaper than what sailors have to do.


1 oz. system treats 30 gallons, $14.99

  • Chemical treatment
  • Tastes great
  • Won’t remove particulates

What it does. This small two-part chemical treatment kills 99.9% of all bacteria, viruses, and cysts by the chemical reaction when drops from each bottle are mixed – creating safe chlorine dioxide. Mix seven drops from each bottle into the cap, wait five minutes, add to your water, wait another 5-15 minutes, and drink up.

At times I got away with using two drops of each and only waiting five minutes if I trusted the water source.

As for the taste.  I’m from Lake Tahoe. Tahoe tap water is without a doubt the most delicious water in the world.  I’m spoiled.  Then I met Aquamira. I don’t know how, but this water tastes like pure joy. Don’t throw Aquamira into the “chemical treatments are yucky” category because it doesn’t belong there.  It gives Tahoe tap a run for its money.

What it doesn’t do. Filter particulates or provide an immediate indication of how many drops are left in the bottles.
The fix. I bought a tiny plastic funnel to keep in my pack. I line the funnel with a bandana and filter the water through the bandana and into my bottle. The funnel is only necessary because my bottles have small mouths; you won’t need one with a wide-mouth container.  As for measuring the drops, the only way to know how much more water you can treat is by transferring the drops to another container and counting them out.

sawyerminiSawyer Mini

Small 2 ounce filter treats up to 100,000 gallons, $20.90

  • Same technology in hand-pump filters
  • Needs some experimentation to find a convenient setup for you
  • Won’t remove nasty taste from dirty water

What it does. High pressure (squeezing or suction) forces dirty water in your bottle through extremely dense, porous fibers. These fibers catch all the bad stuff and only let the water through, removing 99.9999% of all bacteria, cysts, and viruses. It works on the same principle as regular pump filters, just in a smaller container and without the mechanical pump action.

You can either screw this filter onto the mouth of your water bottle and drink out of it like a straw, or use the integral hose connectors to install this filter inline into the hose of your hydration bladder (like a Camelbak).

To keep this filter in tip-top shape, you’ll need to backwash it every so often.  Kit comes with a backwash syringe.

What it doesn’t do. Remove the nasty dirt taste from dirty water!
The fix. Invest in some potent flavored drink mixes or add Aquamira.


Five-ounce electrical purifier good for 8,000 treatments, $84.99

  • Same technology used by municipal drinking plants
  • Easy to use
  • Like all electrical devices, prone to failure without warning

What it does.  Uses invisible UV-C light rays to kill 99.9% of all bacteria, viruses, and cysts found in water.  Municipal drinking water plants use this same technology (as well as the chlorine dioxide in Aquamira).

You put the device in a bottle, flip the switch, and the lamp works its magic.  An indicator light will tell you when treatment is complete.  Due to the size of the device, this will only work with large-mouth bottles like Nalgenes.  It won’t fit in small pouch-type water containers.

One set of batteries will treat approximately 50 liters of water.

What it doesn’t do.  Work all the time?  I haven’t used this system personally.  I’ve heard plenty of reports though that it can be finicky at times, like any mechanical or electrical system, and prone to failure.  It also won’t filter out particulates in the water.
The fix.  Carry a backup lightweight water filtration system because your life depends on it.  You can also filter out water particulates using a bandana over the mouth of your bottle, or purchase one of the SteriPEN prefilters.

My Thoughts

As I said, I haven’t used the SteriPEN.  I don’t want to rely on an electrical device like that.  I have used both Aquamira and the Sawyer Mini quite a bit to determine which one I like more.

I used Aquamira during my thru-hike of the John Muir Trail and loved it. I had to wait 5-15 minutes before I could drink the water, depending on the source, but it was very easy to use. Most of the time I didn’t even have to filter it through a bandana with the clean water sources I had. I could keep it in my hip belt pocket and treat water without ever taking my pack off.  Convenient and light.

Then, with three days left, one of the two bottles leaked in my pack and I didn’t have the Mini as a backup. I had to, embarrassingly, borrow a filter from fellow hikers.

The Sawyer Mini is a great concept and I suppose it’s probably the best backpacking filter option for Camelbak-type systems, but that’s not what I use. It kinda works as a straw when used with a bottle like the Platypus, but then when you want to use that water for cooking, you have to squeeze until your hand cramps up (I suppose you could just boil it for a few minutes).

Sawyer Mini

Squeezing water through the Sawyer Mini into another water bottle.

And after tasting what the Aquamira can do to water, I don’t know if I can taste dirty water again!

So I guess I have my solution.

Keep the Aquamira for water treatment.  And in case a bottle would ever leak again, also carry a Sawyer Mini as a backup filter.

These two options together weigh all but 4 ounces, still half of what a pump filter weighs, and taking up less than half the space.  As far as I’m concerned, these are the best ultra lightweight water filters for backpacking.

Lightweight water filtration

My lineup of lightweight water treatment – the Sawyer Mini and Aquamira

What do you do differently?