Home / Gear Reviews / 5 Star Reviews / Aqua Mira Water Purification Drops

Aqua Mira Water Purification Drops

Aqua Mira Water Purification Drops
Aqua Mira Water Purification Drops

Aquamira Water Purification Drops

Treatment Capacity
Ease of Use


Aquamira drops purify 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

I have always been fascinated by the topic of water purification and filtration because learning how to treat my own water in the backcountry made it possible for me to extend my day hikes indefinitely, beyond the water I could carry in my backpack. That meant I could take bigger adventures, hike longer distances, and opened the door to multi-day backpacking trips.

My current water filtration/purification system consists of two components: a Sawyer Squeeze water filter that I use in conjunction with a 3L Platypus reservoir and chlorine dioxide chemical purification. I mainly use the Sawyer to resupply during the day when I want fresh water without having to wait for a chemical reaction, and chemicals at night when I want to purify a big batch for use the following morning. The two solutions also serve as fall backs for each other, if either breaks or fails, which has happened occasionally on my longer backpacking trips.

Chlorine Dioxide Tablets

For the past few years, I’ve been using Katadyn Micropur chlorine dioxode tablets which are individually wrapped in small foil packages – one for each liter of water.  I’d never tried Aqua Mira Purification drops, probably because my REI doesn’t carry them, which in retrospect is a bad reason. But I was on a few trips this summer where the Katadyn Micropur tablets failed to dissolve overnight in my water bladder. This happened on multiple trips from different water sources. I was very surprised by this but luckily had my Sawyer filter along as a fall back, so it didn’t force me off the trail.

Chlorine Dioxide Solution

When the opportunity to try Aqua Mira’s liquid purification drops came along, I was skeptical that I’d like a liquid solution that required carrying two bottles of fluid, mixing them together, and waiting for 5 minutes for them to react before I could add them to purify my water.

That’s how Aqua Mira works. You combine 8 drops from Bottle A with 8 drops from Bottle B for each liter you want to purify, wait 5 minutes for the combined solution to turn yellow, and then pour it into your untreated water bottle or reservoir. After mixing, you need to wait another 15-30 minutes for Aqua Mira to kill Guardia, Cryptosporidum, bacteria and viruses, depending on the water temperature and turbidity before you can drink your water – but you can continue hiking while you wait.

Mixture of Drops from Bottle A and Bottle B
Mixture of Drops from Bottle A and Bottle B

When I tried Aqua Mira for the first time, I was co-leading a beginner backpacking group with about 10 people in it. None of the participants had brought along water filters or chemical purifiers of their own, so it was up to me to provide them with Aqua Mira drops when they needed to resupply their water.

They were all using 1 L Platypus soft bottles with the same plastic cap and this process turned out to be very efficient because they left their reservoir caps in the same place on the side of the stream, allowing me to fill each of them with drops from Bottle A and then Bottle B en masse. When they returned with untreated water, they poured the ready solution from one of the caps into their reservoir. We continued hiking, noting that we had to wait another 15 minutes before their water would be safe to drink, and calling a group water break when the time had passed. That experience was an eye opener for me because it showed me that drop-based solution was as quick to deploy as a tablet-based one, and far more time efficient for a large group of people.

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
Aquamira CIO2 TabletsChlorine DioxideYesYesYesYes

It’s also far less expensive: one package of Aqua Mira drops costs $15 ($12.50 on Amazon) and can treat 120 liters of water or 30 gallons. Treating the same quantity of water with Katadyn Micropur tablets costs 4 times as much.

After that trip, I’ve continued using Aqua Mira for my own personal use on day hikes, backpacks, and bushwhacks with the following key benefits:

  • No extra trash to sort out or carry
  • Immediately clear that the Aqua Mira solution is good when it turns yellow

Needless to say, I am an Aqua Mira convert and carry those two little bottles on all of my trips now.

Chlorine Dioxide

If you’re unfamiliar with Chlorine Dioxide for treating backcountry water, it’s a well established disinfectant that works by releasing nascent oxygen, a highly active form of oxygen, which is a strong oxidant and a powerful germicidal agent. Chlorine dioxide is 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.

Updated 2016.
Editor's note: Help support this site by making your next gear purchase through one of the links above. Click a link, buy what you need, and the seller will contribute a portion of the purchase price to support SectionHiker's unsponsored gear reviews, articles, and hiking guides.

Most Popular Searches

  • aquamira
  • aqua mira
  • water purification drops


  1. Aquamira is good stuff. It’s rare for it not to be in the pack on every trip. Aquamira is one of those rare products that have so many advantages and so few disadvantages that will put it in the hiking gear Hall of Fame some day.

  2. Aquamira is the best, lightest, quickest solution I’ve found. I also would have probably used it earlier but no REI carries it. Ju
    While hiking the AT, the Steripen I was using called it quits in Hot Springs, NC and I grabbed Aquamira as an economical replacement and it turned out to be a great choice!
    Every outfitter on the East coast, including hostels with supply closets carry it! EMS, and LL Bean too. I’m baffled why REI doesn’t, as none of their stores I’ve been in has had any.

  3. I notice in that EPA study that the chlorine dioxide was totally ineffective below around forty degrees, totally effective above sixty, with the in between not studied. Does the label mention this? If you get water from a spring runoff stream that’s pretty important info, that aquamira doesn’t kill anything reliably in water under sixty degrees.

    • That study just shows that it doesn’t purify cryptosporidium within 30 minutes at lower temperature which is what you’d expect from a chemical reaction. It will kill them if you can warm your water or you are willing to wait much longer for them chemical reaction to take place. If you are in a hurry and can only get cold water, use a filter.

  4. Thanks for your post. I’ve always had at least two filters on group hikes in case one fails.

    How does it affect the taste of the water? Is the taste like other chlorine treatments?. Would you recommend this in an Emergency supplies kit – will it’s shelf life be indefinately since it in two parts to be combined?

    I’m putting together a Emergency supply kit for our home and would consider this a good product to have included.

    Thanks and love this site!!

    • Chlorine dioxide doesn’t have chlorine in it, so it’s really a completely different animal despite the naming similarity. I don’t taste any disinfectant flavor when I drink water treated with Aqua Mira, but I can smell it when I open a bottle or reservoir that’s been purified overnight. the shelf life is 4 years and yes, it is an excellent addition to an emergency preparedness kit.

  5. I’ve been using the drops for a while now and I don’t even carry a backup filter. At least not yet. At the time this was one of the cheapest solutions for water treatment which is why I went with it. Cheap and light weight, you have no excuse not to toss it in a pocket in your pack just in case you need to resupply on a day hike. I think I might get a cheap filter though for this summer. Something like a frontier pro that is small and inexpensive.

    • If you have to get water from a crappy water source with a lot of particulate in it, you need a filter because the chlorine dixoide molecules will bond with the particulates and won’t purify your water. The frontier pro is a good affordable solution – I used one for about 2 years before upgrading to the sawyer.

    • FYI, the Frontier Pro will only get cysts, not bacteria, so don’t rely on it to be your only source of purification. It would be good for pre-filtering though.

  6. I am curious how your water system works. I assume you use the Platy 3L to carry your water in while you are hiking; I do the same. I assume you use the Sawyer filter to (1) fill the Platy and (2) water for cooking. I don’t see where the drops fit in unless you are using both the Sawyer and the drops.



    • Nope – do it differently. I carry two x one liter plastic water bottles – just recycled soda bottles. I drink from them during the day. When I resupply my water, I fill up my 3 L platy, screw on the sawyer filter and squeeze my water clean – into the one liter bottles. After dinner, I fill the platy and add drops, so I have cooking water and water for my bottle in the morning and can escape camp quickly. If I need to carry extra water, I carry it in the platy and the bottles. Platy is nice because it folds flat when not in use and will hold up to 3.5 liters of water. This system works great for dry camps too. Why not use 1L platy soft bottles instead? – I find it easier to reach back and pull the soda bottles out of my packs side pockets – and get them back in without stopping.

      I rarely use the sawyer and the drops together because New England backcountry water is pretty clean and plentiful.

  7. I carry chemicals for emergency use. Otherwise I don’t want to destroy the wonderful taste of mountain water so my Sweetwater is great.

  8. > Faster Cryptosporidium treatment time than Micropur (30 minutes vs 4 hours)

    That is incorrect. It takes the same amount of time regardless of which version of ClO2 you use because the concentrations are the same. The 4 hours is for cold and dirty water, though crypto really isn’t much concern for most areas.

    • I think that’s an unknown, but fair conclusion. Micropur doesn’t make any claims except that it takes 4 hours to kill crypto without specifying water quality or temp and Aqua Mira got the EPA to test that it was effective in 30 minutes at 20 Centigrade. I’ve removed the bullet point because my original conclusion was unconclusive and possibly misleading – thanks for pointing that out and for mentioning that most people don’t have to worry about Crypto anyway.

  9. I’ve used them for the last couple of years. I’m very happy with it as a solution to purifying water in the backcountry. I do not carry a backup system.

  10. Yeah, AM drops are as good as the tabs, but, no better.

    I use a couple tiny 1/4oz bottles that I keep in my pocket. This reduces the wait time to about 3 minutes at streams. I also use a smaller cup. A small chapstik cap works well. This lets me hold small amounts (4 drops and 4 drops) a bit easier, too. I save about an ounce and a half over the standard bottles…sort’o like cutting the handle off a tooth brush.

    I use two .5L water bottles, soo, most streams give me a refill. I carry a larger (~2L platypus) for those times I need more (over night somewhere.)

    Note that Crypto is usually found anywhere there is a sewage treatment plant. It is not considered as a polutant. Most rivers and lakes have some possibility of the bug. In the mountains, streams are fairly pure. Bacteria can make you sick, but is usually not a problem. As the climate warms, more and more Gardia is being found in the mountain streams. Spores can be difficult to kill for either Gardia or Crypto.

    I carry only AM drops. I can boil water if I need to. The stove and AM drops are not related but act as backups for water if I need it. I’ve been using these for over ten years and they seem to work. At least, I’ve never been sick from the craps in the woods.

    I cannot taste AM drops. My daughter says she can. It does add a small bit of salt to the water, soo, there is a slight taste change.

    At about 1oz for a two week supply, they are the lightest I have found. Of course, I also drink coffee in the morning (boiled) and cook at night. I also bring the Steripen for fast packing. Doing peaks means you really don’t want to stop to do water at every stream, so I save about 10-15minutes per day. It is slightly heavier, though.

    • I have found aquamira to be very effective and efficient. By rotating 1L Platy bottles i have a constant supply of potable water. For even faster efficiency, part of my camp routine in the morning, while I eat breakfast, I pre mix the solution in a small (3ml) separate dropper bottle that i carry in my pocket. When I arrive at a water source, I fill up, add the pre mixed solution to the water and keep on moving. This is usually good for 4 liters of water. Then make another batch during one of my rest or snack breaks. This really helps cut down the time i spend at a water source.

      All credit for this one goes to Mike Clelland!

  11. I heard through an AMC 3-Season Hiking Course that the actual literature included in the Aqua Mira package makes no claims about its actual effectiveness in terms of time/temp/turbidity on a various number of pathogens. That is why REI may not carry it.

    I could be mistaken.

    The general hiker community seems to endorse the product, and so I’d consider using it in addition to a mechanical filtration system which doesn’t treat viruses.

    • I don’t think that the Aqua Mira package actually claims that the drops treat anything but the flavor of the water. It may be they do, certainly chlorine dioxide does, but no claims or guarantees. I still use an old Katadyn pocket filter most times – the AM makes the water taste metallic.

  12. just curious if you have a reason to use the sawyer squeeze over the frontier pro?
    i took the rubber “sheath” and cap off my frontier and it’s down to ~1.8oz
    i combine with aquamira…

    i’m assuming it’s due to pore size, and filtration ability?
    looks like sawyer squeeze is rated at absolute 0.01um and frontier pro rated at max 0.3um, but it’s hard to get good comparable numbers.

    • My sawyer filter is a purifier. I think it’s the point one.cant remember. That is probably the main reason. It also can be back flushed and is rather for many more gallons than the frontier pro.

  13. We used Aqua Mira on a 12 person Sierra trek. The tablets would have been a few hundred dollars.

    I estimated the time for filtering water, and it was about two filter-hours per day, assuming the filters didn’t get too clogged and allowing time for daily maintenance. That is not how I want to spend my time in the wilderness.

    We found that Aqua Mira took almost no extra time. Everyone would line up their water bottles or bladders, I’d make up an Aqua Mira mix for each one (we brought a bunch of small cups, like for cough syrup) while the water crew took the bottles down to be filled. By the time they got back, the solution was ready, we’d dose the water and let it sit overnight. Any mid-day refills worked the same way.

    • Walter – for scientific articles, my preference is a refereed article over one published by the scientist’s self published magazine. That and after reading years of pseudo science articles out of BPL – “where 5 guys all tried this backpack while walking on a treadmill”, I’ll stick to Nature and EPA test reports of purifier efficiacy, if it’s all the same.

  14. I realize this is an old post and maybe no one is following it. I’ve used AM for about 1 year now to great effect. Lighter and faster than a pump, no clogged filter with ensuing maintenance headaches, and for me, no taste what so ever. I am considering a simple pre-filter system for challenging sources, but so far everything has worked fine. My question is this, has anyone ever heard of of someone getting sick when using AM according to directions? I never have. Hypothetical hubbub regarding efficacy seems like debating the number of angels that can dance on the head of pin if no one is getting sick using the stuff.

    • I have never heard of anyone getting sick from aqua Mira when it is used according to directions. I believe the recommended concentration is the same as used by most municipal water supplies.

  15. Are you asking about people getting sick because Aquamira did not kill cysts or because Aquamira was toxic?

    As Philip points out, the concentrations are similar to municipal water treatment, so toxicity does not seem to be a problem.

    Chlorine dioxide is moderately effective against cysts, so there is some protection. A 1.0 micron filter would filter them out, improving that. It probably would not clog up as fast as finer filters. Or you can treat water before bed, time will increase the effectiveness.

    The CDC has a great summary on backcountry water treatment:


  16. Thanks to both of you for your response. Walter, your right, my question wasn’t clearly stated. I was wondering if anyone has anecdotal reports of illness due to contaminated water while using Aqua Mira, not toxicity due to chlorine dioxide. I’m just curious to compare real world results vs. lab results such as the refreshingly simple and straight forward CDC report you linked to. Personally, I tend to have the constitution of a feral dog, pretty bullet proof. I am concerned with taking good care of the people hike with.

  17. Leaving the water filter at home this coming weekend and using only aqua mira to clean water that I’m filtering with a bit of cheese cloth (to keep debris out). Having trust issues with things I can’t see (chemicals / magic light pens) but we’ll see how it goes! It’s gotta be better than lugging around that heavy filter.

  18. Joe, we recently spent two weeks in the GC backcountry and came to an issue with the water filter we normally rely on and resorted to using AM treatments for the majority of the trip. By the second day of using AM we all noticed a similar putrid occurrence in our digestion. After much discussion we could only assume that the AM had likely annihilated our microbial gut ecology as well as anything that was potentially in the water. I am still experiencing some digestive disorder but trying my best to reintroduce as many probiotics as possible. This is not to say however that AM is ineffective or a poor trail choice, just beware of such potential effects.

  19. Chlorine dioxide is neutralized long before passing through the stomach. Chlorine dioxide does not enter the blood stream like an antibiotic and ruin the natural flora of the intestines. Chlorine dioxide is the same chemical used by municipal water treatment plants across the country. Does drinking city supplied tap water cause intestinal disturbances?
    I’m not denying that your party had the gut gurgles, but I am sceptical that correctly using Aqua Mira had anything to do with it.

  20. I like the idea of using the bottle caps when you have a lot of water to treat. For bottles that have an attached cap, like nalgenes or some hydration bladders, carry the little cups that come with cough syrup. Those are very light and they stack.

  21. I’m trying to get a system to use for thru hike of pct. In the Sierra the aquamira seems like a waste do to the low temps of the water. I hate to ask but should I go with a filter and the drops??

    • I would, but there are also huge sections of the PCT with more temperate and blazing hot temps. One thing to consider will be sediment and floaters in the water out west. I’d seriously consider using a system with some kind of pre-filter so you don’t clog your filter and render it useless.

  22. John Ladd has been doing a yearly survey of John Muir Trail (JMT) hikers. He’s still compiling the 2015 results, but you can read about gear failures in 2014 at the link below. I was surprised at the number of water filter failures. I expect them to be used wrong. After you drop the “clean” outlet hose in the dirt, you should disinfect it, right? Never seen that done.


Leave a Reply

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