Best water purification tablets (and other portable purifiers)
Cheap, light, small, and easy to use: throw some of these portable purifiers in all of your kits.[See the full post at: Best water purification tablets (and other portable purifiers)]
Stanford X - May 26, 2020
Do the chemicals in the MICROPUR MP1 stop working after their expiration date? My package says it expired 01/2019 and I bought it less than four years ago- they don’t tell you the expiration date when buying online.
Could somebody also say something about using bleach since I’ve read that bleach “expires” after about six months. Do they mean opened versus unopened and will it still be worth using after expiration date if nothing else should be available?
Thomas GomezStaff - May 26, 2020
Hello Stanford X,
Sorry those tablets were old. Chlorine dioxide (Micropur MP1/Potable Aqua) will break down and lose its ability to purify water after five years. This is because the chemical compounds that destroy bacteria, viruses, and protozoa have broken down to the point where they are ineffective. Bleach (sodium hypochlorite) is shelf-stable for six months, then will start to lose its effectiveness regardless if it has been opened or not. Light and heat will speed up the degradation of bleach, so it should be stored in a cool dark place.
One neat product we talked about in the article was the Potable Aqua PURE electrolytic water purification system. It allows you to make sodium hypochlorite (bleach) on-demand, so you never have to worry about shelf life. If you are in a SHTF scenario– if the bleach still smells, like bleach, it will have some germicidal properties. I would filter your water through a cloth filter, add your old bleach and wait four hours. After four hours, if there is still a concern about water safety, boil your water for a minute or two. In general when it comes to bleach, use two drops of non-scented household bleach per quart or liter. Let it work for at least 30 minutes before drinking. Thank you for your questions. Hope this finds you well.
David Salahi - May 26, 2020
In the article above it says:
“… think is pretty neat, is the Potable Aqua Pure Electrolytic Water Purification System. You mix common salt and water in a small container, making a sort of brine solution, which you then add to the device. You select how much water you want to purify. The machine then creates a sodium chloride solution — essentially household bleach — that is just as effective for water treatment and takes as much time (most in 30 minutes, everything in four hours) as any other recommended product.”
I think you meant to say “The machine then creates a sodium hypochlorite solution.” Not sodium chloride which, of course, is just salt water.
Thomas GomezStaff - May 26, 2020
Corrected. Thank you David!
10 Canadian Winters - May 27, 2020
MSR also makes a Chroline maker, but is much less portable.
https://www.msrgear.com/ca/products/global-health/se200-community-chlorine-maker/10275.html and is much more expensive.
Thomas GomezStaff - May 27, 2020
We came across the MSR Community Chlorine maker in our research. Awesome piece of kit for the home, or if you have mobile power. We are looking at getting one in for review. Hope this finds you well.
Sun Yeti - June 16, 2020
Why no discussion of membrane filters (such a Sawyer Squeeze)? For my camping/bugout system, I run the water through a membrane filter, then blast the filtered water with a UV pen (such as SteriPen). I sometimes pre-filter by letting the water settle or pouring it through cloth if it’s really high turbidity (cloudy, muddy), but usually that’s not necessary.
That two-stage system covers pretty much everything besides chemical contamination, and is a belt-and-suspenders approach for most things (either alone should be sufficient for bacteria, for example). The water is ready to drink right away, has no unpleasant chlorine taste, and as long as you can recharge your UV pen, you aren’t going to run out of anything (both the membrane filter and the UV pen are rated for an absurdly large amount of water). Really, the only downside is having to make sure the water doesn’t freeze inside the membrane filter (if it freezes in there, the ice crystals can puncture the membrane).
Thomas GomezStaff - June 17, 2020
Hello Sun Yeti,
We discussed filters in our Best portable survival water filters article. This article was about non-filter methods of water purification.
Your method of water purification is awesome! I do the exact the same thing, with the exact same products. Hope this finds you well.
WF654 - July 13, 2020
Just a few points and questions:
1) “If you only treat water through purification, you’ll likely still have particulates floating around. You’ll survive, but that can gross out a lot of people.” Ain’t that wrong? The more turbid (“dirty”) your water is, the less effective chemical purification is, up to ineffective if turbid enough. Particulates not only shield pathogens from the UV light, but use up the active oxidisers, so there might not be enough left to kill all the pathogens. You should always use clear water if possible, not even with UV, but chemical purifiers as well. Pre-filtering will also extend the life of any filter.
2) When using chemical purifiers, it seems ClO2 is better than chlorine products and more effective against crypto? They seem to work differently (it’s still an oxidiser, but) e.g. https://www.lenntech.com/library/clo2/chlorine-dioxide.htm
3) It looks like Katadyn Micropur MP1 tablets, Potable Aqua ClO2 tablets and possibly Aquamira Water purifier tablets (not so sure about these) are all the same product, made by one company with the same active ingredients (source: EPA database).
4) For removing pollutants (not pathogens), you mention flocculants but forgot activated carbon filters? These would complement each other nicely with more polluted water.
5) If you are using chlorine products (not ClO2), ascorbic acid (Vitamin C) can neutralise residual chlorine taste (but add it just before drinking). It’s even used industrially for that.
6) Remember that none of these treatments are suitable for water that’s going to be stored for long. Pathogens can multiply, after all.
7) Proper boiling is still the best against pathogens, it’s just the huge energy needs…
Thomas GomezStaff - July 13, 2020
Thank you for your comments and insight. This article was about non-filtration methods of water purification and we specifically mention that a combination of filtration and chemical or UV purification is the best approach. Hope this finds you well.
Clark Thompson - April 27, 2021
Anyone else have experience with the GRAYL filter? I recently got one and I find it convenient and it takes roughly the same space as a water bottle with the advantage of a built in filtration system that easily can be used to refill other containers
Gideon ParkerStaff - April 30, 2021
Hello Clark. Thank you for bringing up the Grayl filter.
In our Best portable water filters article we touched on and tested the Grayl ultralight.
It is a popular and well reviewed filter being able to filter out viruses and metals. And like you mention, the ability to refill other containers is something that something like the Lifestraw filter isn’t able to do. But with only being able to filter 40 gallons per filter, and some other concerns we have seen from other people like leaks and cross-contamination it might not be the best for a survival situation.
For EDC though and for treating daily questionable water, it is a great solution. I like that it is discrete, you don’t have a huge tactical filter straw sticking out of a normal bottle and won’t draw extra attention to yourself because it looks like a normal water bottle. I’m glad that you have found that it works so well for you and you like it.
Do you find the water tasting better due to the charcoal filter?
Clark Thompson - April 30, 2021
I am typically filtering steam water that generally tastes pretty good, I haven’t used the Grayl for standing water that taste might be an issue. On the cross contamination front, I’m typically wiping the edges and my hands with an alcohol swab and being careful putting it back together. One thing the Grayl is super convenient for is questionable tap water—not a survival problem but it beats everything else for travel. 40 gallons isn’t a ton, but for me I’m generally starting out with at least a couple liters of water, so the Grayl is a backup. And if 40 days goes by without access to clean water, a water filter probably isn’t going to be your biggest problem…
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