This post may contain affiliate links.

Aquamira Water Treatment Drops Review

Aquamira Water Treatment Review

Aquamira Water Treatment is a liquid chlorine dioxide solution that many backpackers use to purify and disinfect backcountry water sources like streams, ponds, lakes, and rivers. If you’re unfamiliar with chlorine dioxide, it’s a well-established disinfectant that works by releasing a highly active form of oxygen, which is a strong oxidant and a powerful germicidal agent.

Aquamira Water Treatment Drops

Treatment Capacity
Ease of Use

Reliable and Fast Water Purification

Aquamira liquid water treatment purifies water using chlorine dioxide which kills all bacteria, viruses, and protozoa. They're tasteless and fast acting and won't stain your bottles or hands.

Shop Now

Chlorine dioxide has been widely used by municipal water treatment plants to kill a variety of waterborne pathogens since the late 1940s but is iodine and chlorine free.  Chlorine dioxide is a significantly stronger oxidant than iodine, with greater pathogen-killing power. Unlike iodine, chlorine dioxide does not discolor water, nor does it give water an unpleasant taste. It also doesn’t leave behind any by-products in treated water, unlike other purification agents like bleach or iodine.

Aquamira is best used with clear water that doesn’t have sediment or suspended solids in it. It comes packed in two bottles, labeled Part A & Part B. To administer it to your water, you mix 7 drops from Bottle A with 7 drops from Bottle B for each liter of water you want to purify. The two bottles come with an extra bottle cap for you to mix the solution together. One mixed, you wait 5 minutes for the combined solution to turn yellow before pouring it into the water you want to purify. The two bottles contain enough solution will treat up to 30 gallons of water. Aquamira will also purify any container that your treated water comes in contact with, including bottle caps, water reservoirs, hydration system hoses, or bite valves.

After mixing, you need to wait another 15 minutes for Aquamira to kill bacteria and viruses, including Giardia and Norovirus, or 30 minutes if your water is very cold because it takes the chemical reaction longer to occur. If Cryptosporidium is present or a concern, the treatment time is 4 hours. How do you know if Cryptosporidium is present in your area? Ask the agency that manages the area, like the local Park Service or Forest Service. Other knowledgeable local backpackers should also know, but it pays to ask around.

Mixture of Drops from Bottle A and Bottle B

Backup Water Purification

My water filtration/purification system consists of two components: a Sawyer Squeeze water filter that I use in conjunction with a 2L Platypus reservoir, plastic soda/water bottles, and Aquamira water treatment drops. Most of the water I encounter during trips is crystal clear stream water with very little sediment,  suspended solids, or viruses so I can filter it with a simple water filter like the Squeeze.

I carry Aquamira as a backup to the Squeeze in case it fails or gets impossibly clogged in the field. I also use Aquamira drops to batch purify several liters at a time, especially overnight in preparation for the next morning, or when I don’t feel like squeezing multiple liters through my filter. Aquamira also gives me a complete purification solution if I discover that I’ve entered a territory where Cryptosporidium is a concern, without the need to carry a much heavier water purifier like an MSR Guardian all the time. Aquamira drops also have a shelf life of 4 years, so you can carry the same batch season all season and into the next if you have any left at year’s end.

Chlorine Dioxide Drops Vs Tablets

I like carrying Aquamira drops instead of chlorine dioxide tablets because they work about twice as fast since the chlorine dioxide is already in liquid form when it’s added to the water and doesn’t have to dissolve first. I carried tablets for many years previously but found that:

  1. The packets create a lot of small trash that I’d rather not deal with on a trip.
  2. The packet requires scissors to open. Not difficult, but an extra step, and something to keep track of.
  3. That the tablets would occasionally not dissolve.
  4. Chlorine dioxide tablets are about 4 times more costly than water treatment drops

Comparable Chemical Water Purification Products

ProductActive IngredientVirusesBacteriaGiardiaCryptosporidium
Potable Aqua Iodine TabletsIodineYesYesNoNo
Potable Aqua Iodine and PA+ Plus TabletsIodineYesYesNoNo
Polar Pure Iodine CrystalsIodineYesYesNoNo
Potable Aqua CIO2 TabletsChlorine DioxideYesYesYesYes
Katdyn Micropur TabletsChlorine DioxideYesYesYesYes
Aquamira CIO2 LiquidChlorine DioxideYesYesYesYes


I turned into a backpacker the day I learned how to filter and purify water during a day hike. I can still remember that day when I realized that I could take hikes that exceeded the capacity of my hydration reservoir without having to worry about running out of water.  Since then, I’ve experimented with many different filters, UV light, and chemical water purifiers looking for the perfect system that works the best for me and the water I usually encounter on my hikes. Anyone who tells you there is one best water treatment system is just plain wrong. Each technique or device has its own strengths and weaknesses depending on a wide range of factors ranging from water turbidity, the amount you want to process each time, your group size, known organisms in the water, water temperature, level of effort, wait time, and cost.

Aquamira water treatment drops are a good water purification option when you don’t want to carry a bulky water filter or purifier, when the water you want to treat is not turbid or filled with suspended sediment, or you’re concerned about viruses that your water filter is unable to remove (since you can use the filter and then the Aquamira is a two-stage process). Personally, I like to carry Aquamira as a batch and backup water treatment option, but I know people who carry it as their only option since it’s so lightweight. The stuff works well and I depend on it to stay healthy.

Updated 2024.

SectionHiker is reader-supported. We only make money if you purchase a product through our affiliate links. Help us continue to test and write unsponsored and independent gear reviews, beginner FAQs, and free hiking guides.


  1. I used Aquamira as my sole purification method on the AT in 2015. Turbidity was an issue on only a couple of occasions but for those I pre-filtered the water using a fine mesh filter funnel sold by Steripen for use with the Steripen UV water sterilizer.
    I remain a fan of Aquamira especially, as Philip pointed out, for it’s utility in sterilizing a large volume of water overnight with no more effort than is needed to sterilize a more modest amount.
    The occasional criticism heard, that it’s so much slower than filtering, is not a practical issue to me as the job’s done in the time I’ve put up my tent, inflated my sleeping pad and laid out my sleeping bag.

  2. Will Aqua Mira freeze in winter?

  3. I have used Aquamira as my sole water treatment for about 20 years, on the AT and elsewhere. I carried a Sawyer for a few years as a backup and because they got so popular that it felt like it was against the law to not carry one. But I gave mine to a friend after I realized I never used it. By the way, Philip, I’m a working lawyer and I get probably 500 emails a week, and this one is the only one worth reading. Thanks to you I hike with a Seek Outside pack, and my 6’4″ body sleeps comfortably in a Hammock Gear hammock. I saw recently that our first aid kits are fraternal twins. Thanks so much for your time and work, and your clear and insightful reviews. You’ve convinced me to try a non-Gore-tex jacket and to be more mindful about ticks.

  4. Ever since my First Need filter (the 1.0 version) broke, I started using AquaMira. That was more than 20 years ago. And it worked fine, except for the time when I was hiking in the US southwest, where I discovered that a deer jumped into the cistern I was planning to drink from. The deer jumped in weeks before, and wasn’t very good at getting out.

    When I hiked the Long Trail two years ago I was the only hiker I saw that used AquaMira. Everyone else had some version of the Sawyer Squeeze.

    Since then I went the filter route as my primary means of purification. I prefer this as I don’t have to be mosquito bait for the five minutes of prep time. And I don’t have a watch to time the five (or twenty) minutes.

    But the combination of filter, AquaMira, and boiling my dinner and drink water is the perfect combination.

    • Loved the deer story!

      My father traveled the world doing geology/geophysical work and would run survey camps in the wilds and jungles for weeks to months at a time. He told the story of getting the camp’s water supply from a river and observing a dead camel float by as soon as they finished. I’m sure there’s a ‘cameling up’ joke in there for the taking!

  5. I’ve gone to AquaMira as my primary in the mountain west. A filter is still part of my kit in cattle country. I carry a small clear dropper bottle which lets me mix several dose at once. My understanding is that efficacy declines over time but is still effective within 24 hours. (The clear bottle provides visual confimation that the mix is a proper yellow color from Part A and Part B.) At a stream I’ll fill one or two bottles, add drops, and keep hiking. Tough to camel up at the creek, but ok 20 minutes later. By mixing a day all at once I can save a fair amount of time.

  6. Hi,
    I need your advice –
    In an emergency, I may need to drink water from a pond out back. While at home, I have access to my
    aquamira chlorine dioxide drops and my Alexapure Pro water filter. Do I need both? Can I do one or the other, drops or filter ? Or, should I treat the water with the Aquamira drops first and then filter it ?
    Jeff Garn
    Estero, Fl.

    • I don’t know what’s in your water, but if there are a lot of suspended solids, I’d filter it and then treat it with aqua mira. The latter because if its near people, it may have crypto in it. To be safe, wait 4 hours after that.

Leave a Reply

Your email address will not be published. Required fields are marked *