• Comments (67)

    • 7
      Jonnie PekelnyContributor - January 19, 2019

      What is the typical use for a filtered water bottle in an emergency situation? Is the idea that you’re scooping up dirty or otherwise untreated water from a water source and just sipping it through the filter in the water bottle? Then don’t you have basically a contaminated water bottle?

      • 5
        John AdamaStaff - January 29, 2019

        Correct, and you’re thinking through it well. You can also have a separate dirty water vessel that you pour into the filtered bottle as a way to keep more of the outside/lip of the filter bottle clean.

        There’s no black and white “right” answer to how to do this, it’s just a matter of thinking through it for your setup, which is why we touch on it in the article.

    • 2
      Hal Dey - January 22, 2019

      Is there an activated charcoal filter available to be used with an in-line filter (piggy-back style)?
      Somewhat along the lines of source (bladder, bottle, whatever) – hose – in-line filter (go-flow, Sawyer, whatever) – hose – charcoal filter(for taste, chemicals, etc.) – hose – mouthpiece. (Order not significant)
      Basically I’m looking for particle, biological, taste filtration that’s portable.

      • 6
        John AdamaStaff - January 29, 2019

        Many of the models above have a charcoal/carbon filter for taste as part of the overall product. Particularly the straws (whereas the inline filters tend not to). The HydroBlu Sidekick is an example.

        Nothing comes to mind for a stand-alone charcoal filter you can splice in as you described. It’s not a bad idea and should work, but it’s not something we’ve researched.

      • 4
        squirrel - June 5, 2020

        Check out the Platypus GravityWorks Carbon Element (good for 300 liters) or the Katadyn Carbon Cartridge (refillable, good for 200 liters or 6 months).

    • 5
      heatherjasper - February 8, 2019

      Thanks for the information about the HydroBlu kit. I only heard about their Sidekick, but not the Versa. I have replaced the Sawyer gravity kit and the Mini with the Versa kit in my Amazon shopping list; can’t wait to get it!
      Have you heard about the Oxgord Aqua Marina straw? Do you have any opinions on it?

      • 7
        John AdamaStaff - February 12, 2019

        Would love to hear what you think of the Versa once you test it, especially since you used the Sawyer too (it’s essentially a contest between the HB Versa and S Mini). I’m not familiar with the Oxgord, but just checked it out and it smells like a white-labeled me-too product you should avoid.

    • 7
      Jim Befit - June 9, 2019

      PLEASE EXPLAIN yourself, there are soo many battery powered UV lights available. If on the run so to speak, it’s quick, could be rechargeable with a solar battery charger which is versatile! And long term important. What is considered living organisms? what about fecal matter- is it living organism’s? are the LED UV’S not powerful enough? Aren’t VIRUSES considered living?? Seems like an efficient way to kill those. Thank you.

      • 7
        John AdamaStaff - June 10, 2019

        You don’t see many experienced preppers rely on a UV light because there’s too many breakable parts and points of failure, they aren’t as rugged or versatile as other options, you won’t get the overall volume from a UV the way you would from a Sawyer etc, and the UV doesn’t remove particulates.

        Yes, fecal matter can have living organisms. Whether or not viruses are considered alive is a debate, but its okay in short-hand to refer to viruses as living. https://askabiologist.asu.e…

      • 5
        Jim Befit - June 12, 2019

        ok, not trying to be argumentative, just not yet satisfied. yes, UV doesn’t remove particles, Kinda no brainer, But if you remove particles but not virus’s-( the most difficult and expensive part you said,) but can kill viruses with a $5-$20 UV LED light, why not? Too many pieces? Have you seen how durable LED flashlights ARE? Some are LED/UV Flashlights. if you can’t afford a .001(?) filter, can’t hurt to use one LED-UV after particle filter so you can to kill living organisms?
        Thank you for your last reply, read from you soon.
        Jim

      • 6
        John AdamaStaff - June 12, 2019

        It’s certainly workable to buy a cheaper filter that handles bacteria etc but not viruses, then boil or use a UV pen on the post-filtered water to kill the rest. It’s just not what we and the experts we interview for these stories like to recommend for most people — I have yet to see a UV product that makes me think “yeah, I’d rather carry this in my go bag than the HydroBlu/Sawyer/etc.” There’s almost never a Singular Right Answer in prepping, so do what works for you.

        p.s. keep in mind that viruses are very much an outlier concern in American water supplies.

      • 5
        Dan Ello - March 25, 2020
        [comment deleted]
    • 6
      Karen Kory - July 12, 2019

      John, thanks for this incredible article.
      One question, are you not concerned with claims that some of these producers make (like HydroBlu) that are not substantiated by test results (other than some Chinese no-name lab) or certification? Seems like these recommended products look awesome, but since their use could be in a life-threatening situation, it’s a lot to rely on ‘their word’ imho.

      • 7
        John AdamaStaff - July 13, 2019

        Thanks Karen, and high five for being skeptical about those kinds of company marketing claims. We always are as well.

        I hope to one day do a proper scientific test, where we try different types of contaminated water with various filters and send the results to a lab for verification. For now, we’ve used a skeptical eye for b.s. (we’ve got a pretty good nose for it), read through lab reports provided to us by manufacturers (can also smell the b.s. reports), interview the managers (shady ones typically won’t get on the phone with press), and cross-checked with any other user reports around the web of giardia etc after use.

        That mix is enough to make us comfortable, and it’s a lot more than most ‘reviews’ you see on the web.

        Frankly, even when something is third-party certified, you still run risks. There’s just no way to remove all possible risk. Just last month we found that a manufacturer with full military certification was actually sending sub-standard product, because their supplier changed the previously-certified materials without letting the company know.

      • 4
        Karen Kory - July 13, 2019

        Ugh… I bet stuff like that does happen,more than we’d like to know — especially with China manufacturing (at least according to my husband’s very frustrating production experiences there). Thanks for the speedy reply and all your great work. Invaluable, and much appreciated.

    • 7
      Bill Coulam - September 16, 2019

      This is one of the best articles I’ve ever seen on water filtering and purification. Really well done research and organization. I’m surprised nothing from RapidPure showed up here in your review. A company out of Minnesota. Fantastic capacity, unbeatable flow rate, and 6-log virus-removal to boot. Last time I checked, their site was rapidpure.net. Did you already know about their stuff and exclude it for some reason? I think they’ve been around since at least 2012.

      • 6
        John AdamaStaff - October 2, 2019

        Thank you. RapidPure wasn’t excluded for a particular reason, so I’ll add to the list for future consideration. Are you affiliated with them?

      • 6
        Bill Coulam - October 4, 2019

        Nope. Just a fellow preparedness aficionado.

    • 7
      KC - November 28, 2019

      My problem is a good filtration system for my get home bags.  Because the bags are stored in the car, they are exposed to freezing temperatures in the winter, which renders most of what you reviewed useless as the filters are destroyed if they are frozen.  Perhaps one of these is not susceptible to freezing?  I haven’t gone through every single one, but from what I have found so far they all have that problem.  Right now my thought is coffee filters for large particles and water purification tablets (can those be frozen?).  Any thoughts?

      • 7
        John AdamaStaff - December 2, 2019

        You’re right that most any filter is at risk of freeze damage — filters by nature use small engineered pores to block the bad stuff, and engineering at that small level can be damaged. But as far as I know, the real freeze risk is from leftover water inside the filter, so if you either have an unused filter* or can let it dry out after use (which is good practice anyway), a dry filter should be okay in your car over winter.

        *unused: You should always use your emergency gear before an emergency, but since many people have multiple of the same filters (in their BOB, GHB, etc.), then you could leave the unused one for the car.

        Otherwise yes, some combo of a coffee filter / some other filter that can remove visible particles + purification tabs are the way to go. (We haven’t done a post on those tablets yet, but they are in BOB/GHB lists and we’ll do a specific post on them soon.)

      • 4
        Alicia - June 17, 2020

        The Guardian states it can be frozen. Pricy but fits the requirements.

        “Extremely Durable: Engineered to withstand heavy use, freezing, drops*, and harsh environments.”

    • 7
      Philip - December 7, 2019

      John, I just discovered this site last night. Wow! Extremely impressed with your work. Newbie question: since I live a block from the sea, do any of these products desalinate as well or should I just focus on that process (which would mostly purify as well)? Any suggestions on desalination?

      • 8
        John AdamaStaff - December 8, 2019

        Thanks so much for the kind words, glad it’s helpful! Great question, and one we were just working on the last few days for an upcoming project. Salt water is the only real exception to the standard “use a filter + purifier” prepper setup, as these products don’t remove salt. Desal is the best option, and for many folks that means using evaporation.

    • 8
      Dan Ello - March 25, 2020

      Thank you for the great site.  Is it still deemed not generally necessary to purchase a purifier that can handle viruses, in light of the coronavirus?  I want to be sure before I purchase a Versa filter/kit.  And if so, is a pump the best/easiest way to purify large amounts of water?  Without this concern I would opt for the HydroBlu Go Flow Gravity Kit.

      • 4
        Ef Rodriguez - March 26, 2020

        Right now there’s no evidence of that anywhere. In theory, it could be transmitted in a water system, but the vectors for that are pretty implausible. A direct quote from the EPA’s page on this topic: “WHO has indicated that ‘there is no evidence to date that COVID-19 virus has been transmitted via sewerage systems, with or without wastewater treatment.’ In short, it’s not a concern.

      • 9
        Mary Jo Groves - April 16, 2020

        Actually, there was a recent study (Lancet Hapatology for original article—https://dgalerts.docguide.com/stability-sars-cov-2-different-environmental-conditions-sars-cov-2-wastewater-and-guidance?nl_ref=newsletter&pk_campaign=newsletter&nl_eventid=35812&nl_campaignid=3720&pw_siteID=25&ncov_site=covid-19) that not only showed coronavirus in water, but that the amount in the water was a predictor for blooming hot spot of virus.  That is, testing the water downstream of a community for viral load, could predict rise in infections in that community. Further, and not well known, is that covid causes a significant number of people to have what appear to be gastrointestinal infections, without the expected respiratory symptoms. MJGroves, MD

    • 5
      David Dabney - April 3, 2020

      Thank you for all your work on this John (et al)! Question: I’ve seen a couple consignment MSR Guardians at my local outdoors shop. Would you be comfortable depending on a used Guardian if there’s no visible damage? Or would you be more confident in using a new but less expensive option? I’d like to get the Guardian eventually but it’s not in the budget at the moment 😀 I guess I could test the water to see if it works, but that would cost more money and I wouldn’t be confident in my results.

      Thanks!

    • 4
      Elizabeth H - April 5, 2020

      Do you have any thoughts on the Grayl Geopress Water Purifier Water Bottle? I know you said you weren’t the biggest fan of the Ultralight Water Purifier Bottle from Grayl, and I was wondering if you had the same reservations about the Geopress. I was thinking of getting one for my bug out bag and killing two birds with one stone by getting a bottle and filter in one. I have an MSR Guardian, but would like something cheaper to have in my bag. Great article by the way…very informative and helpful!

      • 7
        John AdamaStaff - July 18, 2020

        Unfortunately we’ve not yet had hands on the Geopress. Did you end up getting it, and if so, what do you think?

    • 7
      Uhlan - July 1, 2020

      Glad to see the Katadyn Pocket made the short list.  The terms used in the article, “Venerable” and “Built like a tank,” are worthy appellations for a product that’s been my go-to filter since my first backpacking trip as a kid back in the 80s, and that one is still in working order today.

    • 4
      Lowell - June 28, 2021

      At the top of the article, you list the following trio as an example “upgrade” mix:

      Upgrade: MSR Guardian pump + HydroBlu Go Flow gravity kit + LifeSaver Legacy bottle = $480

      The MSR Guardian I understand: it has virus protection, high flow rate, and works well for shallow water sources.

      The HydroBlu Go Flow gravity kit I also understand as a complement to the pump, because in situations where you aren’t worried about viruses and water is plentiful or deep, you can filter lots of water with little effort.

      What I don’t understand is the LifeSaver Legacy bottle, or any bottle for that matter. What benefit would this or any bottle add to the Guardian + HydroBlu gravity combo, which combined allows me to tackle viruses and shallow water if need be, but also passively filter lots of water if the situation allows? 

      I’ve already got 38oz of potable water stored in a single-walled stainless steel Nalgene in my kit. If I get the Guardian and HydroBlu gravity, why would I add a filter bottle?

      Thank you for your time and effort as always John 💝

      • 3
        Alicia - July 1, 2021

        I would like to hear John’s response as well. The advantage that comes to mind is speed. Situations may arise where you  need to basically dip and drink on the go.  Neither the Guardian nor the Hydroblu are quick as they need setup and time to pump or flow.  But now that I read the article again, the Hydroblu can be put on a standard bottle – just not any that I have in my BOB.  Hmmmmm.  So really looking forward to John’s response. 

      • 3
        John AdamaStaff - July 5, 2021

        Hola amigos! Such great questions / thinking. The answer will probably be underwhelming 🙂

        The trio doesn’t give you any “scientific” advantage over the duo, since as you said, you can cover all of your main threats with the non-bottles.

        Alicia’s note about being on-the-go is part of the answer. It’s essentially about the form factor of having a bottle, even though bottles aren’t great overall, because once you’ve got the basics covered it’s nice to have something self-contained and portable (which also increases redundancy).

        So the “upgrade” in that sense is not an upgrade in technical power, but in form factor variety and how it enables more more use-cases.

    • 3
      Lowell - July 29, 2021

      I just tried my HydroBlu Go Flow Gravity Kit for the first time, and was surprised to find that the valve on the bag is placed along the side of the kit, which means that the bottom ~10% of water in the bag basically sits there if you hang the bag from its top.

      Do y’all have any idea why this is?

      Do y’all just fill it all the way up, wait until it can’t dump any more water by itself, then dump out the remaining water?

      • 1
        Olly Wright - August 11, 2021

        I have a hydroblu filter, but not that particular gravity kit. I wouldn’t try tilting the bag to filter out that remaining 10% because it is designed that way for a reason. 

        My educated guess is that if you fill that bag with lake/pond water, you will be getting some sticks, dirt, and bugs in there with your water. Those will hopefully settle in that lower 10% area and not go through your filter. If the spout was at the bottom of the bag, you would have an entire layer of dirt trying to go through your filter. The hydroblu can filter out that dirt, but it’s easier on the filter to not have to. Just dump and rinse out the bag of the accumulation at the bottom and fill up again.

        Is the gravity bag pretty durable or do you think it can get punctured in an emergency situation?

    • 4
      Mark M - August 11, 2021

      Katadyn Combi is the best filter on this list for prepping imho, especially if you live on a farm or the countryside. Water will be extremely dirty in a SHTF situation, and less-robust filters and straws won’t last rigorous use. 

      • 2
        Olly Wright - August 11, 2021

        For particularly yucky dirty water another user on the forum brought to my attention a millbank bag to act as a prefilter. Here’s the link for that post. I’m adding one to my kit because like you said, during SHTF our water sources will get even dirtier with more people using them.

      • 3
        Mark M - August 11, 2021

        The Combi actually comes with a pre-filter that goes on the end of its hose, but I just put a coffee filter over it with a rubber band for extra protection and ease of cleanup.

        Not only is the Katadyn Combi a silver ceramic/carbon filter, it is also the hardiest and most durable on this list, bar none. Those pen filters and bag filters may be rated for 100,000 gallons, but they’ll never last long enough to make it past 1/10th of that number in real world use. The Combi was even standard issue to the Swiss military mountain units. There’s a reason why Combis are $200 and Sawyers are $20.

        The drawbacks of the Combi are weight, size, moving parts, price, the fact that it needs a hose, and that it was recently discontinued by Katadyn in favor of the less-effective, $400 Katadyn Pocket (sheesh).

        The silver ceramic replacement filters are expensive. Each Combi filter costs about $100 and lasts for 13,000 gallons; so you won’t need but a few, and deals may be had as retailers sell off their remaining inventory. Every new Combi comes with both a ceramic and carbon filter installed.

        The Combi offers carbon filtration, and in a SHTF scenario filtering chemicals out of the water may be even more important that killing pathogens.

        Even with the drawbacks this filter shines amongst the others.

      • 2
        Olly Wright - August 11, 2021

        That does sound like a good filter and one that would be reliable. The carbon filtration is an additional benefit to improve the taste as well. 

        A Sawyer will make me some clean water, but it’s still going to taste like pond scum… yuck!

    • 3
      AS - September 19, 2021

      First, thank you for all of the great information on this site.  I have several different water filters for various hiking/backpacking needs, namely the Katadyn hiker for when I know I will be filtering water (longer trips) and a couple of sawyer minis that we carry in addition to water for emergency backup while hiking/backpacking.  After doing a ton of research in preparation for an upcoming trip in which filtration and purification are desirable, I came upon grayl bottles, which are filters(debris, bacteria, Protozoa), purifiers (viruses), and they also remove heavy metal contamination.  These claims have supposedly been verified by independent labs and meets EPA/NSF/ANSI standards.  They are highly durable and very easy to use.  While the filter life isn’t stellar (65 gal or 3 years, whichever comes first), it seems like the ideal purifier for an emergency situation.  Unopened filters last 10 years. For those of us living in/around cities, one would have to assume some degree of heavy metal contamination and likely viral contamination in streams/run off/parking lot puddles or whatever other water source is available in an emergency.  I wouldn’t want to rely on just filtration in this situation.  I don’t believe all chemical purifiers remove heavy metals either (just P&G as far as I’m aware).  At $90 per bottle and $30 per replacement filter, the cost per gallon is significantly higher than a lot of other filters, but there aren’t many options out there that offer this level of protection.  

      • 2
        Gideon ParkerStaff - September 20, 2021

        Thank you for your great comment. It’s good to see that you are protecting yourself with a bit of redundancy of carrying a backup Sawyer and not relying totally on the Katadyn.

        Also glad to hear you are enjoying your Grayl bottle filter. We did review the  Grayl Ultralight model in this article and did like the virus and metal protection. However, we have some suspicions about the long term durability with the unique “french press” motion. How long have you used yours and have you run into any issues so far?

      • 3
        Alicia - September 20, 2021

        +1 the here on appreciation for the post and interest in its durability.  I wondered if any of your experience @AS or the TP testing @Gideon included filtering pool water.  That is one large reservoir next door versus the natural reservoir a mile or so away. The Sagan Life filter that works with a Aquabrick is rated to filter 500 gallons of pool water.  It’s definitely not a backpacking option, but looks easy to use in the more likely shelter at home long term scenario.

      • 3
        Gideon ParkerStaff - September 21, 2021

        Alicia, pools can be a great source of emergency water for cleaning, bathing, or flushing the toilet, but because of the chemicals in it, it’s not the best for drinking. Filters that are able to filter out chemicals usually have lower life spans like the 500 gallon Sagan.

        Distilling pool water is a possibility but requires a lot of fuel to get the amount you need. Solar distillation is slow and doesn’t produce very much either.

        Having multiple methods of water collection and treatment is the best way to go. Here’s an example:

        • Use pool water for bathing and cleaning.
        • Use your home storage of potable water for drinking.
        • Have a rain catchment system and filter through a cheaper and longer lasting filter like a Katadyn.
        • Take a trip down to that reservoir once a week and fill up water that will be used just for drinking.
        • Use a small solar distillation system to provide a small amount of clean pool water.
        • Have a Sagan Life Filter as a last ditch resort for treating pool water.
      • 2
        AS - March 15, 2022

        I’ve been using it for 8 months now and have not had any durability issues.  It has been dropped numerous times and other than a few scuffs, its completely fine.  I’m very happy with it and have started taking it as my primary water filter.  The only thing I would suggest is keeping a small zip top bag with it for situations in which the outer shell of the bottle doesn’t easily fit into the water source.  

    • 3
      Gideon ParkerStaff - September 27, 2021

      Pasting a note from a reader:

      “Hello, I read The Prepared almost every day. I noticed the review guide on portable water filters states about the Katadyn Hiker that Katadyn says it is not for backcountry use. I just received one I ordered from REI and didn’t see that statement in the manual. I also haven’t seen any such statement online in a quick Google search. The closest thing I saw in the manual was a warning not to use it in brackish water or water with chemical contamination. I suggest checking and maybe correcting your statement.”

      —–

      Thank you for your catching that and bringing it to our attention. I reached out to Katadyn and they responded with:

      “…All of our water filters, including the Hiker, can be used in the backcountry.
      And really were designed for exactly that…”

      I have since updated our article to reflect that the Katadyn Hiker water filter is able to treat backcountry water sources.

    • 2
      Hans - March 15, 2022

      Thanks for all the great info. I understand viruses aren’t a major threat in US waterways currently, but what are the primary reasons for that (and thus the possibility for change in the future)? If climate change results in more extreme heat/temperatures in the US and/or if the US were to become “less developed” would we expect viruses to be more of a threat? Now that the Katadyn Pocket and MSR Guardian are the same price, debating whether the “tankiness” of the Katadyn Pocket is worth the lack of virus protection.

      • 4
        AS - March 15, 2022

        So the primary reason viruses are a threat in underdeveloped countries is because much of their water is contaminated with untreated human waste.  These viruses typically result in diarrheal illnesses, which further contaminates the water supply.  Any place where untreated sewage can mix with drinking water will have the potential to have viral, bacterial, and protozoan contamination.  This is a chronic issue in areas that lack basic infrastructure, but could easily become an issue almost anywhere if a major disaster were to occur.  If your water filter is just for hiking/backpacking in areas with low human population, good sanitation practices, etc, no viral filtration is needed. If you just want one filter that would cover a disaster situation, viral protection would probably be important.  Of course, you can always use chemical decontamination as a backup if the filter you have doesn’t protect against viruses.

      • 2
        Hans - March 15, 2022

        That’s helpful, thanks!

    • 3
      underprepraccoon - April 28, 2022

      Where I live, there’s already a decent amount of heavy metals in the water as it’s mostly deep well water and there are mines all over. I would expect it to get worse if grid down in summer and winter, and extra low water table in winter a la Texas freeze 2021. Everything is in water tanks but I’m not sure how much it’s processed before being put there.

      I’m also not sure if I would trust surface water out here anymore (think Church Rock tailings spill, among other things).

      Ideally I think the Alexapur gravity would be optimal, even for a built set up instead of factory. But like, that capability in a portable package that isn’t an absurd cost isn’t available with lab confirmation. It’s also not portable enough.

      I would like to start with a portable device that would do heavy metals at least, but all the carbon filters aren’t specific about what they can and can’t do.II figure the recommended with the carbon filter, and the PNG purifier of water powder seems to be the only practical solution, but there are also no specifics on the purifier of water capabilities.

      So does the recommended gravity kit, purifier of water mix and just investing in way more water storage seem more realistic?

      I could also use the recommended kit on the stored water if there was any contamination as well. I’m just frazzled trying to find the better solution for what I need and stay in budget, black outs are happening more and I want to round out my preps while I can

      • 3
        Gideon ParkerStaff - April 28, 2022

        Filtering heavy metals isn’t a feature in most portable water filters, but it’s good that you are aware that it is a concern for you and is something you need in your filter. 

        From the article, here are the filters that have some heavy metal protection:

      • 3
        underprepraccoon - April 28, 2022

        Thank you for the recommendations.

        After digging into the ones that aren’t bottles, the survivor filter pump and the recommended straw filter seem well enough.

        I couldn’t find any lab test info on the MSR mini works and the life straw only was tested for lead.

        The Survivor pro was tested for lead, mercury and cadmium. While those tests are 7 or so years old now, if it’s still the same technology, it should work.

        It’s not as effective as the Alexapur, but it’s better than everything else for this specific case.

        I also wish I could do my own testing, I have the skill set for it, but not the certifications.

        Might as well not take the risk of something lesser, there’s rumblings the local hospital might close soon, so higher echelon care won’t be as accessible so can’t risk anything lesser.

        Should probably invest more in my medical kit too

      • 2
        Gideon ParkerStaff - April 29, 2022

        Sounds like you have a good plan laid out there. You should do your own testing. You don’t have to be certified to test your own water and know if it is safe for you and your family to drink. 

      • 3
        Agnes - May 10, 2022

        Thanks for the great article.

        I didn’t see a mention of this anywhere on the site, so I wanted to share. The Puralytics Solarbag is tested for viruses, heavy metals, petrochemicals, urine and all sorts of other stuff. Approved by EPA, WHO etc:

        https://www.engineeringforchange.org/wp-content/uploads/2015/08/SolarBag-Technical-Reports-18-Mar-2015.pdf

        There is a list at the end for all the contaminants it is tested for. It requires sunlight but still works on cloudy days, just takes longer.

        Quote from the linked pdf: “It is the only portable, non-powered water purifier that meets and exceeds the World Health Organization (WHO) standards for a highly protective device.”

      • 2
        Bradical - May 10, 2022

        I know the sun can sanitize water left in something as simple as a disposable water bottle or ziplock bag so at first I thought this wasn’t anything special and just a plastic bag with a cap. But when you mentioned that it gets rid of heavy metals, I looked into it more and there is a lining inside the bag that reacts to the sun and breaks down those heavy metals and other chemicals. 

        The bag says it only lasts 500 uses or after 7 years, so that lining seems to break down over time but if the bag stays in tact, it should still be able to kill viruses and bacteria. Cool product. At $60 though and the 7 year shelf life, I would almost want a manual filter that lasts indefinitely on the shelf and filters much quicker than the 3-6 hours this takes to clean 3 liters. 

        Sorry if I’m being dismissive, but just seems like a lot of money for a plastic bag. Do you have one and have used it before?

      • 2
        Agnes - May 10, 2022

        No worries. That’s part of the reason why I posted, I was curious about more experienced ppl’s opinions.

        I have one that I currently only use when we have power outages in my area, which happens about 1-2x a year after the winter/summer storms. So no heavy use so far. I live in the city, if anything ever happened to our water supply it would be full of everything you can think of. I didn’t find any filter with a longer list of tested substances, so I liked it as a backup solution. I wouldn’t use it as my sole option.

        I was planning to take it camping this year to do more testing.

        The Malawi study showed that it was good for >1000 uses so ~3000+ liters but that’s obviously still limited. Then again, the MSR Guardian filter is good for 10000+ liters. Price-wise that seems comparable.

        When I was deciding on filters to buy I had read that the MSR filter also has a shelf life of 5 years or so but I can’t find that any more right now. So maybe the info is outdated.

      • 2
        Bradical - May 10, 2022

        The SolarBag certainly is impressive with it’s large list of things it has been tested on, multiple pages worth on that PDF! I like how there are no moving parts, extremely lightweight, and dead simple to use. 

        That’s great you have been putting yours to use. I’ve been thinking about the bag all day since you introduced me to it and I’ve been very interested in it.  

    • 3
      Michaël - October 18, 2022

      Hello,

      Great website, with much useful information!

      My plan is to go cycling and wildlife/birdwatching through everywhere in South-East Asia for more than a year, in Indo-China, Phillipines, Indonesia, etc. The dream is to end up in Papua New-Guinea.

      While cycling in hot weather I drink about 10 liters of water a day. I don’t want to, and in many remote places I wouldn’t even be able to, buy water bottles for all of that. In Europe (and Georgia, Caucasus, where I’m now traveling) I can use my loyal Sawyer Squeeze filter and filter unlimited amounts of water everywhere, both through a big gravity system or squeezing by hand.

      But unfortuntely, the Sawyer Squeeze doesn’t filter viruses out of the water, so it’s only a partial solution for South-East Asia. I don’t know whether it’s possible to buy chlorine dioxide pills/ liquid in many places in South-East Asia and I don’t want to lug around too much. I also don’t like the chemical taste and don’t know whether it’s healthy to use in large quantities for extended periods of time. I could buy a Steripen, but you can treat only one liter of water at a time, you would have to filter the water anyway, and you need to bring multiple spare batteries and possibly another light bulb.

      My main options for now are the pumps Survivor Filter Pro X and MSR Guardian, or electrified chemical purifiers Aqua Research H2gO Prime and the Potable Aqua Pure.

      The Survivor Filter Pro X seems awesome. It produces very clean (0.01 main filter) and tasty (carbon filter) water without effort (electronic). The downsides are that it is fairly bulky and heavy and, I’ll need one or two carbon filters and, most importantly, that it’s an electronic device and I’m a bit hesistant in placing all my trust for clean water for a year into that. A good option would be to order the manual convertion kit with it. So that, if something happens, you can still manually pump. But it will add even more to the weight and bulkiness of the set-up and the flow rate for manually pumping is really low (0.5 l per minute), which means 20 minutes of pumping for ten liters. So, I wouldn’t want to do that for extended periods.

      An alternative would be the MSR Guardian, which is a fully manual pump with an exceptional flow rate of 2.5 l per minute. The downsides are that is is even bulkier and heavier than the Survivor Pro X (without the manual back-up kit), that is has only a 0.02 main filter (compared to 0.01 for the Survivor) and that it is super expensive (almost 400 dollars). It also does not have a carbon filter, so the water will taste less good. Furthermore, there are reports of the pump breaking, which could be a potential disaster and unexceptional for a pump with a price like that.

      In either case, I might still bring my Sawyer squeeze filter, combined with chemical drops, as a back-up system.

      On the other side are the chemical purifiers Aqua Research H2gO Prime and the Potable Aqua Pure. I couldn’t really find a difference between those two. The upsides are that they are lightweight, you only need salt and that it is easy to pair them with my existing Sawyer Squeeze filtration system. The downsides are that it is chemical, so it makes the water taste less good (although better than usual pills). And from a health perspective I also don’t want to drink a lot of chemically-treated water for a year straight.

      I’m still researching and hesitating a lot. I’ll have to make a decision soon, since I’ll be leaving Georgia, Caucasus, in a month and will travel to Thailand afterwards. So, there’s only one more month to let a device ship (from potentially the US) to Tbilisi.

      Thanks for any help/suggestions!

      Michaël

      • 2
        Gideon ParkerStaff - October 18, 2022

        That sounds like quite the adventure! I wish you safe and smooth travels and wish I could go with you.

        You have some great questions. Looking at the size of three of the virus filters, the Survivor Filter Pro is smaller and lighter than the Pro X or MSR Guardian. 

        Survivor Filter Pro- Size: 6.5 x 3.2 x 2″ Weight: 12.8 oz

        Survivor Filter Pro X- Size:  6 x 5 x 2″ Weight: 13.5 oz

        MSR Guardian- Size: 8.2 x 4.7 x 3.5″ Weight: 17.3 oz

        I know that the electronic component of the Pro X is nice and hassle free, but for being smaller, lighter, cheaper, and not being reliant on electronics, the normal Pro might be a better option for you with the only drawback being manually pumping.

        The MSR does filter faster but doesn’t filter down as far, is much more expensive, heavier, larger, and doesn’t have that carbon filter. The carbon should take out some heavy metals and make the water taste better. VERY important to have your water taste good, otherwise you won’t be as likely to drink it and will be dehydrated. 

        You will need to buy an additional carbon filter for the Pro or Pro X. They last about 2000L, and if you drink 10L a day and will be gone for over a year, that’s 3650+L. 

        If it were me, I would definitely go with the Survivor Filter Pro, get an additional carbon filter, and bring along the Sawyer Squeeze as a backup filter. Don’t rely solely on one filter the whole trip, if it broke you would be in trouble.

    • 1
      Claire - November 30, 2022

      What filters would you recommend in both a bug-in and bug-out scenario for viruses (for a suburban/urban scenario where the water way be contaminated with various pathogens after a major natural disaster or attack)?

      What do you think about the Lifestraw Community filter (https://lifestraw.com/products/lifestraw-community) for a bug-in scenario? (e.g. lasting >weeks)

      • 2
        Gideon ParkerStaff - November 30, 2022

        Hi Claire,

        There are a few options for viruses in bug-in and out situations. Just remember that the risk of contracting a virus from water in America is almost zero in normal life. So think about if you really want to go with a more expensive filter that can do that and also sacrifice for a slower flow rate.

        The best portable survival water filters article has many recommendations for bugging out and a recommendation will depend on your budget and form factor desired. For example, there are straw, pump, and bottle configurations.

        For bugging in, the Best home water filter article has recommendations as well. The Lifestraw Community looks like a great product for providing a lot of potable water to many people for a long time, but something like the Berkey tabletop filter as recommended in that article might be a bit more visually appealing to live on your countertop during every day life and also has the benefit of being a carbon filter which will improve the taste of the water.

      • 2
        Alicia - December 11, 2022

        I just learned a home-sized Berkey isn’t shippable to California.  They’re working on it.  Their third party testing needs to be blessed or something.  

      • 2
        underprepraccoon - December 12, 2022

        I think there’s a possibility this might change, there’s a few pilot programs to start purifying sewer water in Colorado, and with the extreme draught that’s not being mitigated, I could see that happening to a lot more places if the idea takes hold and grid go down

    • 3
      Claire - December 16, 2022

      Hi! Do you have recs for a water filter that you would attach to a faucet in a (longish term) bug-in scenario?

      • 2
        Carlotta SusannaStaff - December 16, 2022

        Hi Claire, you might be interested in these forum posts:

        Whole house water filtration system

        Under-counter water filters

      • 1
        Claire - January 16, 2023

        Thank you! In buying a whole-house water filter, what are the things I should look for it to filter out (eg VOC, cloudiness, etc)? I’m a little overwhelmed! Don’t know if I’m looking for a whole house filter to filter out the same stuff as say a Berkey’s. I live in the suburbs. I want to filter the water for overall health but also want one  in place for shorter and longer term disaster situations. 

      • 1
        Carlotta SusannaStaff - January 17, 2023

        Hi Claire, we’ve obviously been corresponding via email since this message and I wrote to you that no matter if you choose a faucet or whole house filter I would still recommend having a separate backup filter (be it an inline portable filter, a Berkey, etc) in case you can’t get water out of your main pipes. But as for deciding if to get a whole house filter it really depends on your priorities: if you want to filter water for “overall health” then both a whole house filter or a Berkey should do. On top of my head, I think that a difference is that a whole house filter should be able to filter out microplastics, while I’m not sure if a Berkey does. Just keep in mind that microplastics are everywhere now and, not only do we drink them but we also inhale and ingest them all the time. Not trying to steer you in any direction with this, just wanted to reiterate that it depends on your priorities.

        FWIW I live in the ‘burbs as well and right now the only worry we have is that during the summer months, they put more chemicals in the main water supplies to offset the risk of algae that keep popping up in our reservoirs. The water is perfectly safe to drink from the faucet but it tastes a bit of chemicals so we use the Berkey on a daily basis to just improve the overall flavor. We are not thinking too much about microplastics now. We don’t have a whole house filtration system right now because we are happy with the Berkey, which doubles down as an emergency filter, too.

        Having said that, my in-laws live in the mountains and get their water from a well so they actually do have a whole house filtration system but that’s because the burden of treating the water is on them, rather than on a city’s municipality (and they also have spare portable filters as a backup). I’ve also seen posts on social about people living in cabins and getting their water from a creek and just using a Berkey.

        Unfortunately, I can’t really comment on which brand or type of whole house or faucet filter is best; if you have any more specific questions you can ask them in one of those forum posts I linked above, or create a new forum post altogether.