Your work is an incredibly massive breath of fresh air compared to so many of the UA-cam gear review/technique channels that come off overly click baity. Not to mention, I actually learn so much from every video you do! They are packed with incredibly desne, great content, I could watch them multiple times and still learn new things each time... or I could gain a better understanding at something I only grasped the edges of the first go around. Thank you sir!
The pure amount of time invested into this video is wild. Thank you sir, for the AMAZING videos you create. This is literally one of the best, most educational, raw information dump on UA-cam. DUDE, HOW DO I GIVE YOU MY MONEY. I would really love to support you if you have T shirts, Stickers, damn, I’d cash app or Venmo you, out of sheer appreciation of your content. From the bottom of my heart. THANK YOU.
One more thought on sawyer longevity (and probably other hollow fiber filters). With hard water, you have to do a vinegar soak once in a while to maintain flow rate. I think a lot of people don’t know that. I didn’t know when I first started using my Sawyer micro, and I was really disappointed with the flow degradation… then I saw the instruction to do a vinegar soak between trips, and I’ve been much more satisfied since then. Great video! So much good info!
Yes, a vinegar soak brought my 3-year old filter back from the dead at the beginning of last year. I suspect another soak this spring will time it's up for another season.
Dude I am blown away by this video. I fully intended to just grab the highlights but here I am an hour later. I can't believe I am only just now finding your channel. Keep up the great work
The advantage of getting giardia is that, not only did you not need to carry extra water filtration equipment , but you also become lighter through the process.
This informative series is important not only for hikers but for those of us that live in the far back country and have to figure out how to filter and clean the water for our homes. You are a HERO!
Another amazingly high quality video. At this stage I would expect nothing less - you always have such detailed and well researched information! Thank you for putting it all together. I live in Europe and have an Alpkit Hippo filter. It removes 99.9999% waterborne bacteria (E.Coli, Salmonella, Cholera) and 99.99% of protozoa (Giardia, Cryptosporidium). Not as high as the Sawyer but I'm glad it's above EPA standards. It has a lifecycle of up to 3000L apparently.
You absolutely succeed in your goal to have the viewer think again about his past choices. Even though these are "tough" videos based on the amount of information/data you go through I cannot thank you enough in bringing this info in a very very digestible form. I always go on the lookout for more of your videos even though my brain needs quite some time to put everything into place :). Thank you
Dr. Skeptical you are a treasure! With regard to a subsequent video a lot of people are not aware that the early Spanish explorers were not searching for gold but, in fact, were searching for the " Skep's trail mix recipe". Sadly , like the seven cities of gold the recipe was never found. How revolting!
It’s a perfect channel. Since behind, attention to details, understanding our needs, providing data and ideas to think about instead of saying what we need to do, sense of humor. It’s simply awesome!
Fantastic video! This has really changed my perspective on what to look for in a water filter. I'll admit I was very much guilty of assuming that all filters worked "well enough" so the removal numbers didn't matter and just looking at flow rates, cost and ease of use was enough. Funny how epidemiology can be a stark illustration of the importance of a good understanding of statistics! Definitely rethinking my water treatment strategies for backpacking after watching this, so thank you for taking the time to research and present it all!
In addition to possibly the most useful backpacking content I’ve seen on YT, as well as your spirit of generosity in sharing all of your work,I must say I really enjoyed your sense of humor! Many a time did I laugh out loud, catching the little winks (i.e. lake Titicaca) and more obvious jokes (i.e. Must be great cause it shows a picture of backpackers) sprinkled throughout the series. Made it fun and amusing to learn! Bravo
My favorite pedantic youtube nerd ever is back with a new video! Keep up the good work brother. These are exactly the kind of videos UA-cam needs in such a sea of misinformation and click bait. Also a suggestion- Any interest in making a video or series about sleeping bags and warmth ratings? I know there's a lot of confusion out there about advertised temperature ratings versus real ratings. I figured you would be just the kind of guy to give a well thought out, researched and detailed approach to the subject. Cheers, Lou
I’ve been thinking about how different items come together to form your entire sleep environment from your shelter to your sleep clothes to the bag and pad. Also, the idea of bag liners (both inside and/or outside) for a layered approach. I’ll have to put it on the list! Thanks!
Anecdotally being one thru hiker with more than 6000 miles I have never gotten LaGuardia 😂 on my AT NoBo thru hike I started calling it LaGuardia. I even let some folks think I thought that was the actual name and it entertained me to no end. I used polarpure never ending iodine treatment that trip. On the PCT I used aqua Mira drops. Hikers around me did get sick and I noticed most of them didn’t take care of basic their hygiene. Dirty ol dirt bag hikers. Anyway I thought you might enjoy my personal experience with this. I’m also a wilderness guide, WFR, and a Master naturalist. Love the video! 👍👍
Thanks! A lot of the studies I referenced also made the point about hiker hygiene, suggesting that some of what gets blamed on the water really comes from unwashed hands. Don’t reach into someone else’s trail mix! 😉
@@GearSkeptic you read my mind. I thought you might have the same ideas about that. I’ve preached pouring snacks into hands if sharing and have gotten sneered at lol. My wife and I don’t even reach into shared snacks or food. Really appreciate all the work you put into these videos…. The hiker food videos are also top notch.
I use a millbank bag to pre filter when the water is dirty. A sawyer squeeze and aquatabs. If one fails or i some how contaminated the water theres a backup to inshore i don't get sick. And it helps me sleep better at night. To back flush i put 2 aquatabs in a bottle let sit about 45 minutes. And back flush wile tapping the filter until the water is clear. Remember to always tap your filters when cleaning. It makes a world of difference. Ps. Thank you for all your very helpful videos.
My autistic brain that is prone to hyperfixation and going down the rabbit hole for my special interests loves your videos.Thanks for sharing this valuable content with your audience. You must be protected at all costs.
Thankful for the risk reduction afforded by the sawyer filters over the last decade of outdoor adventure! I switched from the mini to the squeeze about 9 years ago for the flow rate benefit like you mention. Glad to see sawyer ranking at the top of these comparisons and that they most openly share lab testing. Great video series!
I started backpacking in the 70s and for about 20 years I never filtered my water. I never got Ill. Then I purchased an MSR pump filter. It was heavy but did the job. As I aged lighter gear has become more important so for about 10 years I used chemicals and I also had no issues. I now use a Sawyer and it’s been good. No issues. For now I am happy. If I was doing something like the PCT I would bring my Sawyer and chemicals. I would filter then treat it. I must add most of my trips take place in the White Mountains of NH and the water sources seem pretty clean. Probably better than the crap from my home tap. Good video, thanks
I've been waiting for this video in particular as I prefer to filter. And after watching, am (mostly) content with my Sawyer Squeeze and Katadyn BeFree filters, though might go with the combined approach in certain circumstances. Thanks for all the time and work you put into your videos! It allows me to save my own many nerdy calculations and much research time for my gardening projects or the occasional acquisition of new gear.
I was excited when I looked at my phone during the Superb Owl game and saw that you had published a video again! This is the kind of quality content I wish I could find on many other kinds of topics, and I'm glad you exist for hiking gear!
I wish everyone in this vertical of youtube had the quality and information you put into your videos. Delivery of the information is top notch as well. I could listen to you all day.
A couple years ago, I took my son and nephew on a 3 day backpacking trip. We only used a sawyer filter and gathered water from a fast flowing river. We used one filter with a large bladder to fill our water bottles. My nephew got giardia and had symptoms for over a month. My son and I were fine. Thanks for your work, chlorine dioxide now added to the treatment regime
Watching this video made me realize I'm not the only one going down these rabbit holes with gear (which is good news as I thought I was crazy). Great video in an even greater series! Thanks for putting out such good content
One thing I'm not understanding well is how these filters have much lower log numbers for cysts, which are bigger, than bacteria, which are tiny. How are cysts getting through holes that stop almost all bacteria? Thank you for the incredible series of videos!
It's a good question that I've never seen addressed. One possibility that occurs to me is the effect of "testing only to the standard". I've noticed that some tests only use an influent water with a concentration to match the log removal they are looking for. They finish with results of "zero" microbes after filtering. In this case, the test wouldn't reveal if the filter can actually do better than that.
I love these videos! My already existing skepticism has been magnified greatly after watching your videos. I'm looking forward to sharing my newly found knowledge with fellow PCT hikers this season.
What a great video! As a former user of the Sawyer Mini the flow rate was unbearable and I would often find myself not using the filter because it was so annoying. Bought the Platypus Quickdraw filter and the difference is like night and day, I almost enjoy using the filter now! Even if the filtration is not as effective atleast I am now filtering the water I drink every time. Don't know about the longevity of the filter yet though, havent used it too much yet.
Haven’t had a chance to use mine yet. Anecdotally, I’ve seen other channels report higher initial flow rate in comparison, but then dropping off faster. Once I figure out a good way to test, I will do a follow up video.
Thank you so much for putting out these videos for us, your work goes above and beyond, so detailed and informative. I’ve got pages and pages of notes from watching your nutrition for hikers series and it’s been really helpful for me, it was like taking a short course! Always look forward to your videos and never thought I’d be excited to see a part 3 to a water treatment video series but here I am! I look forward to part 4 :)
Wow, that's such surprising information about the water from the campground faucet being the highest concentration. That's where i normally fill up. Interesting info!!!
I live in north eastern Nebraska…agriculture and animal husbandry w/cow feed lots abound. I use a water filter as a pre filter then use a water purifier as a final. That way the filter saves my purifier filter and I get higher water volume out of it. Also, I disinfect both filters’ intakes and wash my hands. I back flush as well. Each filter (pump and gravity) is stored in its own carry bag. I’m retired military and a lifelong outdoors gal and saw early on how failure to follow personal hygiene in the field can lead to misery. It only takes a few minutes to filter, wash and store the water filtration systems needed for an outing. Proper waste disposal is required as well. Complacency and laziness are all too common out there.
I'll be honest I didn't watch the whole thing, so I may have missed it, but one important factor to consider is being able to check the integrity of your filter and whether it is still filtering correctly. One of the reasons why I selected the Katadyn BeFree over the Sawyer was because you can blow into it as a test to see if the filter is still good or not. Not sure how good of a test this is, but this is what Katadyn says to do and it does give me more confidence when using it to know that it is still filtering correctly.
Truely masterful research, analysis and interpretation. A sincere thank you for the time that goes make to produce these videos. A lot of information to take on board, but I'm very much enjoying the process.
Very interesting series you have going here. I'm very interested to see your take on Steripen. Efficacy of the Steripen looks good on the surface, but you really dig into the details and I'd love to learn what you uncover. One thing that I frequently see mentioned, but never quantified, is that UV sterilizes rather than kills and that some pathogens can reactivate after a period of time. I've never been able to find any indication on how long that might be and to what degree. I'm also wondering if you've done any looking at small micron monofilament nylon mesh filter bags. 25 micron bags are relatively easy to source and have great flow rates. Smaller micron bags are available, but a bit tougher to source and based on my experience with both 75 micron and 25 micron bags, I would expect affect on the flow rate to be noticeable at much below 25 micron. It just so happens that 25 microns is small enough to filter out some of the larger unfriendly bugs (some protozoan cysts, for example) and does a great job of removing particulate that might otherwise hide the bugs from the UV light. We've been using a 25 micron bag for the last few years as a particulate pre-filter for a Steripen while hoping that we were also gaining some level of purification help as well. Either way, they do a great job of removing the wonderful floaties in the water and they are super light at around 4g for the one we use. Regarding your comment at the end about using a filter more than once on the same batch of water to increase effectiveness, I have to wonder why some of the harmful critters made it through the first pass. I'm actually quite curious why the filter process isn't more pass/fail. Is it because any bugs larger than the filter pores fail to make it through, but ones that are the runts of the litter fly right through with no problem? If that is the case, I would expect the second pass through the filter to accomplish very little. Is it instead because the filter has a small number of "defects" where the pore size is either larger than expected or a failure in the medium causes that same effect? In that case, multiple passes through the filter might result the same percentage of pathogens taking the freeway each time, but with the overall population reduced on each pass. That might also explain why the filter fails to filter the larger pathogens at 100%. The Sawyer datasheet you included suggests the former as they seem to claim the latter is not possible. They go as far as to say "No harmful bacteria, protozoa, or cysts can pass through the SawyerPointOne Filter" and that "No pore is larger than 0.1 in the Sawyer PointOneFilter." If the largest pore size is 0.1 micron (μm), how on earth do we have these little guys making it through? From en.wikipedia.org/wiki/Bacillus_subtilis, "B. subtilis cells are typically rod-shaped, and are about 4-10 micrometers (μm) long and 0.25-1.0 μm in diameter". www.ncbi.nlm.nih.gov/pmc/articles/PMC8123537/ indicates the size of R. terrigena to be 1-2 micron. www.tandfonline.com/doi/pdf/10.1080/23311932.2019.1569830 says it's "cell shape was short rod, with cell length of ... 1.60 ± 0.08 μm." Unfortunately, they don't give a diameter, but a photo of a slide from the first article suggests the rods to be maybe 2-3 times as long as they are wide. That would put the low end of diameter at about 0.51 micron. M. luteus also seems to have a size of around 0.5 micron. That's at least a full 5 times larger for the last two than what the Sawyer should "Absolute"ly filter out. Something has to give since a few of the bugs are still making it through. I wonder what it is?
Very interesting ideas! I’m always inclined to say that it’s not restricted to just one option. All those things might be going on simultaneously: No manufacturing process is perfect. Hole size will vary. Living things aren’t exactly alike. Some will be bigger or smaller than the average. Nothing is ever perfectly ordered. They way in which irregularly-shaped organisms address the filter media will differ. I would expect all of these things on your excellent list to contribute to less-than-perfect results. Let me add another: cells aren’t immaculately rigid. Consider a basket full of water balloons. The balloons might not fall through the holes of the basket under simple gravity. But, push on a squishy balloon hard enough and you might force some through. I wonder about the role of pressure and the rate of pass-through for microbial threats…every time I see somebody squeezing the bag on their filter system so hard it pops.
Thank you very much for your nice review, I love it... But, us I am another "skeptical", in this peer review context that UA-cam provides, here it is what I missed: when speaking about filtration "size matters". Reduction provided by hollow fiber filters depends both on the average size of the tiny pores that this hollow fibers have and in the size of the particles that you are intending to eliminate from the water. In this case in the size of the bacteria, protozoa and viruses. Obviously viruses are too small to be retained by the filters, so they are out of the equation. Eukaryotic protozoa cells are much bigger than bacteria cells. So, if a filter claims a reduction of six logs for bacteria, expected reduction for protozoa should be much bigger. IMO, filtering is a safe option for protozoa risk and for bacteria in most circumstances. For worse scenario, combination of filtering first and chemical treatment second would provide a enough safety level. I'm not sure if filtering twice would provide the same safety level: bacteria small enough to pass the pores the first filtration would be able to pas it again in a second filtration. I know that there are other factors influencing this, like distribution of pore size, so more investigation on this would be needed.
My sawyer squeeze got really drippy and slow in the offseason, and my treatment was: backflush with water and vinegar, soak in warm vinegar water for 1-2 hours, the a half dozen hard backflushes with warm water and it was flowing like new again. I did use the syringe, i use the bottle method in the field(with a squeeze bag).
Thanks for this extremely useful video. I was made aware of you by one of my viewers, as I'm addressing water filters right now. I learned a lot. Thanks again and will be watching the other videos as well of course !
Great to see another video from you my friend! Your content is always absolutely excellent, thank you so much for your work and your contributions to this field :))
Timeless work here! A related topic for a guy with admirable patience and curiosity - what happens to these filters when they freeze? I've heard of catastrophic housing failures as well as subtle leaks in the hollow fibers. Some vendors say there is simply no way to test a filter for subtle harm after a freezing event, while others suggest blowing air back through at modest pressure can identify microleaks. (Sawyer claims to test each filter three times during manufacturing. How do they do that?) How hard of a freeze is required to cause a problem? Are all filters equally susceptible? Is there a way to anti-freeze your filter other than keeping it in your sleeping bag? Thanks again for a really informative and enjoyable video!
I carry a BeFree and a Sawyer mini. The BeFree is terrible with dirty water, I prefer to use it on canoe trips when I can scoop "clean" water from the middle of a lake. Once at camp the Sawyer gets setup on a ridge line with a larger feed bag.
this is another great instalment in your water treatment series. i wonder if it would be possible to mention the best ways of eliminating as much as possible crop chemicals or heavy metals in water supplies that may fall foul of agricultural run-off. thank you again for analysis
Definitely! I’m gathering research on adsorption filters and activated carbon for another video. Those technologies will reduce chemicals and heavy metals.
thank you! did i miss where you gave data on the sawyer squeeze? you refer to it constantly, but every time you get into specifics, you only use the mini (but i could have missed!). where does the squeeze sit in your comparison/analysis?
It has the same filtration rates as the mini. Both use Sawyer’s “absolute 0.1 micron” fibers. The Squeeze has a better flow rate, though. I aim to test that in the future.
Excellent information. Somewhere in the gear room, I have a bottle of flocculant concentrate meant for really muddy water, but I don't know much about using it. Might make for good content. My experience with all three Saywers and the Befree is that you will essentially need to replace the filter every 1.5-2ish years if you're a weekend warrior hiker doing 10-20 trips a year. YMMV but I notice no difference between them in service life before they get so agonizingly slow, you can't use or clean them any longer. For pre-filters, I've seen two pretty interesting if fiddly bits. Millbank bags seem to be a British army thing and let you pre-filter solids from the water. I've spoken to someone who swore by using filters meant for making biodiesel. Not a clue if they are safe for drinking water, but they appear to come in fairly fine mesh sizes. I always wondered if I could combine the two products. I purchased something that looks a bit like a condom that goes over the stem of my Befree on Amazon, it didn't end up working with my hydrapak soft bottles so I've never been able to use it.
I am currently building quite a collection of pre-filters. Everything from coffee filters to micron-level meshes and screens. That’s hopefully a future video. You can buy millbank bags for drinking water. They are popular with bushcrafters. I’m also curious about flocculants. Thanks for the reminder!
@@GearSkeptic After much head-scratching, I figured out the flocculant I purchased was an impulse buy after watching "De-silting water treatment for ultralight backpackers" on Jim Pflugrath's channel. It appears to be something other than plain alum which is interesting, but I don't know how the performance compares. I also see Rothco Chlor-Floc on Amazon which sounds interesting and contains a super-secret flocculant with sodium dichloro-isocyanurate. My thought has always been to re-package into a tiny dropper in case a torrential rain turns the stream's super silty. I generally don't have issues with turbidity in the mountains. Protecting the filter from tannins in the water in places like Dolly Sods or the BWCA would be more of a concern.
Might I suggest a vid on silt removal via coagulation?… … it’s an advanced for topic for backpacking, common for rafting rivers, and used ~every minute in ~every water treatment plant worldwide. I suggest comparing the classic flocculant alum to modern polymers.
My interpretation is that Gentry Austin is telling you to pick up your crown because you are the King when it comes to the most thoroughly researched and comprehensively presented videos containing extremely useful information on You Tube. Thanks so much for what you have done and continue to do. Martin.
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Yeah... I'm waiting for this 😘🥳🎉 thank you 😘😘😘😘 greetings from Taiwan 🙋🏼♂️🌴
Love your videos. Thank you for your time and energy! Was also curious about the you make chlorine filters by using salt and electricity. Snd of course uvb filters. Also wondering if leaving your filtered water sitting in direct sunlight how well microorganisms are reduced.
Thanks! I have begun research on both UV pens and solar methods for disinfection. Future videos in this series to come! For the salt/electricity methods (like Miox), it's a novel way to get it, but you basically end up with active chlorine as your disinfectant. If you check out the Part 2 video, there's a description of chlorine vs. other chemicals.
After seeing that hilariously high contamination straight from a faucet; I feel much better about always, regardless of source, filtering through my sawyer.
Big Steripen fan here. I would love to see a comparison of Steripen to Sawyer. I'm just afraid my sawyer squeeze will clog and I won't have any clean water to backflush with. Of course my Steripen could also malfunction. After watching your videos, I'm getting some ClO2 tabs to replace the iodine tabs for a backup.
Odd question referring to your rough math at 37:00 to 37:30. If a CFU consisting of 10 cells were to enter a filter, wouldn't that make it easier for the filter to catch it just on size alone? I guess this entirely depends on how well the cells stick together, or if they easily separate once they reach the filter. This is something that I know literally nothing about(as you can probably tell). Also just want to add this isn't antagonistic, just genuinely curious. Your channel and every one of your videos are amazing and have made my backpacking experiences significantly more enjoyable. truly can't thank you enough.
I think CFUs are something that result from growing microbes artificially in a Petri dish. I’m not sure how well that would translate to the wild. I have read that some things like viruses may not be primarily loose as individuals in backcountry waters. They can tend to cling to larger particles of debris. That could certainly help with their filtration. Real world vs lab gets complicated.
I was looking at using a Sawyer SP160 and after looking at some rather disgusting throughput I found the Katadyn Steripen (sediment) Pre-Filter which will fit on the Sawyers input opening. This, I hope, increases use, longevity, clarity and reduce backflush requirement.
@@GearSkeptic Going on what I've seen, not personally tried: The Steripen fits in a Nalgene filler - which, apparently, is the same size as the Sawyer SP160 inlet.
50:20 Did I understand this right? The Sawyers have the same fibers. And the squeeze filters faster because he has more fibers? I thought if water has to run through more fibers it would flow slower. Or does this mean the squeeze has more volume too and that would reduce the density of the fibers? Very good channel and very logic and scientific approach👍🏿❤️
What were the odds that I would discover such a research heavy channel with such interesting topics right as I start getting into backpacking. I'd say around 5 log
Incredible research. Much respect. One of the complaints that I have seen over many videos is on the CDT where there are stretches of areas that lack water and the sources of water that they do come across even after using many of the filters presented here, is the awefull taste that remains. I imagine that is probably due to the mineral content remaining. Can you address that issue in your research? I am not a chemist so I don't know the size of certain minerals vs pathogens but I would imagine the pathogens are much smaller. So why would you have the aftertaste after using these filters ? Is this some sort of solubility/chemical difference? Wouldn't the minerals be filters out or is that a different type of filter that must be used (e.g. carbon filter)? Have you tried any filters that add the additional feature of aftertaste/mineral removal? One of the response to this other author's prefiltering sediment is that his method cannot remove Tannins. I am not sure what Tannins are chemically but I guess it comes from trees etc.. Are these contaminants harmful to drink? ua-cam.com/video/udzGUXi_gzA/v-deo.html The Meltdownman
Chemicals, dissolved minerals and heavy metals are all very much smaller than pathogens. They go right through a conventional filter. You need activated carbon to remove them, which works by an electrochemical process of adsorption. I am working on that research for the Part 4, because adsorption is also used for viruses. Stay tuned!
I prefer the mini, though people on long hikes tend to end up with a Squeeze (faster flow, filters for longer before clogging, but bigger and heavier). They should all have the same filtration.
@@GearSkeptic perfect thanks! I have only used the mini but don't find the flow rate much of an issue. Thanks for getting back to me, really love your videos!
Fantastic video! Thanks so much! Question: I hike a lot in Europe and most of the hikes I go on have 3 types of water sources. 1) water springs where pipes come out directly out of the ground; 2) cattle/sheep/goat water trough 3) rivers and streams (some fast most moving some slow, some in high elevations some in low, some with in areas with some animal husbandry (cattle, sheep and goats) and other without; I would love to know the concentration of pathogens in these types of environments (particularly 1 and 2). If springs are really clean (as I've been told) presumably I could get by with much less Log protection. Similarly, in the water trough I've seen, I assume the animals do not crap in it (I could be wrong) but put their mouth in it. That being the case, I wonder how much are the pathogen concentrations in this water source type (and what filtration protection I could get by at. BTW, in the last cast I had always used the chloride dioxide tables too (but sort of by chance since I was too grossed out by the water). Your last video on chemical filtration vindicated my hunch (thanks again). Also, these series highlighted the invisible risk of swimming in watering holes that I've seen many hikers jump into (and I've often wanted to as well but mostly don't actually do - particularly still waters).
Check out Part 4 on Ultrafiltration. It goes into the risk of viruses in various types of places, and Part 5 gets further into stuff like the issues with water runoff from farms. Hope that helps!
Questions: 1) Do Squeeze and Mini have identical pathogen removal rates? 2) Dual filters being more realistic than re-filtering a second time, how does Hydroblu-->Mini compare to Mini-->Mini? Surely, the "logs" don't simply add (Hydroblu's 3-log + Mini's 7-log ≠ 10-log?)? Whole-house filters always place filters in descending micron order, 50u-->20u-->10u-->5u for example? Perhaps Hydroblu-->Squeeze for reasonable flow-rate?
I believe Squeeze and Mini have the same filtration rates. They use the same “absolute 0.1 micron” fibers. Squeeze just has more so it can flow faster and take longer to fill up. The question of whether logs of removal simply add is an interesting one that might depend upon why the filter is missing some microbes. If it misses mostly because some few of the fiber holes are too big, I think the logs add. You run the water through again and chances are those microbes that escaped won’t encounter a big hole this time. Those “chances” being the actual filter percent. But, suppose the misses are due to some microbes being smaller than the rest. Smaller, in fact, than the average hole. In that case, it might make little difference to filter a second time, as those little microbes would just make it through again. The reality might be a bit of both, where you get a good amount of additional removal, but not fully like just adding the logs together. I wish I could find some lab tests on that! Mini to Mini should be better than Mini to Hydroblu in any event. I’d put the lower rated filter in front, as it is more like a pre-filter to help prevent clogging of your finest filter. Redundancy in the event of a field failure is never a bad idea.
As usual, great video series! Ignorant question here: Do these filters aid at filtering major particles like say for example a mountain river with lots of sediments in suspension? Is the efficiency reduced?
once again an excellent video, please take the steripen for your next episode ( virus). there is no profound information about this either, except for the advertising statements.
Interesting and wonder if you came across this question being addressed in the literature. How long can giardia parasites remain active in your gut and if it was say 9 days as you mentioned it can take to feel its effect, could it be cumulative and using a filter that has a log 7 filtering ability and only a very small amount got through each day and you drank different sources that this happened, would it be the same as just drinking out of one source with a lower log value of purification at once?
Your work is an incredibly massive breath of fresh air compared to so many of the UA-cam gear review/technique channels that come off overly click baity. Not to mention, I actually learn so much from every video you do! They are packed with incredibly desne, great content, I could watch them multiple times and still learn new things each time... or I could gain a better understanding at something I only grasped the edges of the first go around. Thank you sir!
Thank you! I really do appreciate that. It means a lot!
Glad someone else also said breath of fresh air ;)
Fu stuff here backpacker Sagan!
You are absolutely talking about the things that actually matter and exactly no one else is discussing them.
I figured, since I’m not better than anyone else at talking about the popular topics…I’d better stick to the other stuff 😉
@@GearSkeptic Well, I am diving into your vids slowly. I love them. keep them coming!
The pure amount of time invested into this video is wild. Thank you sir, for the AMAZING videos you create. This is literally one of the best, most educational, raw information dump on UA-cam.
DUDE, HOW DO I GIVE YOU MY MONEY.
I would really love to support you if you have T shirts, Stickers, damn, I’d cash app or Venmo you, out of sheer appreciation of your content.
From the bottom of my heart.
THANK YOU.
That is very generous of you. I really appreciate the thought, but no need! Thanks so much!
Agree, ty soooo much! Saw one of your videos recommended in a current reddit thread & binging your awesome vids.
@@GearSkepticI want a Gear Skeptic sticker to put on my volumetric calorie density optimized bear canister!
One more thought on sawyer longevity (and probably other hollow fiber filters). With hard water, you have to do a vinegar soak once in a while to maintain flow rate. I think a lot of people don’t know that. I didn’t know when I first started using my Sawyer micro, and I was really disappointed with the flow degradation… then I saw the instruction to do a vinegar soak between trips, and I’ve been much more satisfied since then. Great video! So much good info!
Great point! Thanks!
Yes, a vinegar soak brought my 3-year old filter back from the dead at the beginning of last year. I suspect another soak this spring will time it's up for another season.
Thank you, I had not seen this process before!
Just tried that today - works. You would think Sawyer would recommend vinegar flush.
Dude I am blown away by this video. I fully intended to just grab the highlights but here I am an hour later. I can't believe I am only just now finding your channel. Keep up the great work
Thanks! Welcome down the rabbit hole 😉
The advantage of getting giardia is that, not only did you not need to carry extra water filtration equipment , but you also become lighter through the process.
Also, if you’re sick enough for long enough, you don’t even need to hit the trail anymore and be exposed to that nasty water.
The time and effort you've put into this is phenomenal, thank you ♥️
What an amazing video
Thanks very much!
This informative series is important not only for hikers but for those of us that live in the far back country and have to figure out how to filter and clean the water for our homes. You are a HERO!
Thanks so much! If it helps at all, it makes it worth it!
Another amazingly high quality video. At this stage I would expect nothing less - you always have such detailed and well researched information! Thank you for putting it all together.
I live in Europe and have an Alpkit Hippo filter. It removes 99.9999% waterborne bacteria (E.Coli, Salmonella, Cholera) and 99.99% of protozoa (Giardia, Cryptosporidium). Not as high as the Sawyer but I'm glad it's above EPA standards. It has a lifecycle of up to 3000L apparently.
You absolutely succeed in your goal to have the viewer think again about his past choices. Even though these are "tough" videos based on the amount of information/data you go through I cannot thank you enough in bringing this info in a very very digestible form. I always go on the lookout for more of your videos even though my brain needs quite some time to put everything into place :). Thank you
Thanks very much! Very kind of you to say.
Dr. Skeptical you are a treasure! With regard to a subsequent video a lot of people are not aware that the early Spanish explorers were not searching for gold but, in fact, were searching for the " Skep's trail mix recipe". Sadly , like the seven cities of gold the recipe was never found. How revolting!
It’s a perfect channel. Since behind, attention to details, understanding our needs, providing data and ideas to think about instead of saying what we need to do, sense of humor. It’s simply awesome!
Very kind of you, and much appreciated. Thanks!
This is literally the best backpacking channel I have ever found. Thank you for all the effort and time you put in!
Thank you very much! I really appreciate that.
Fantastic video! This has really changed my perspective on what to look for in a water filter. I'll admit I was very much guilty of assuming that all filters worked "well enough" so the removal numbers didn't matter and just looking at flow rates, cost and ease of use was enough. Funny how epidemiology can be a stark illustration of the importance of a good understanding of statistics! Definitely rethinking my water treatment strategies for backpacking after watching this, so thank you for taking the time to research and present it all!
Thanks very much! I’m glad if it can help.
In addition to possibly the most useful backpacking content I’ve seen on YT, as well as your spirit of generosity in sharing all of your work,I must say I really enjoyed your sense of humor! Many a time did I laugh out loud, catching the little winks (i.e. lake Titicaca) and more obvious jokes (i.e. Must be great cause it shows a picture of backpackers) sprinkled throughout the series. Made it fun and amusing to learn! Bravo
Thank you so much! That is very kind of you, and I really appreciate it!
My favorite pedantic youtube nerd ever is back with a new video! Keep up the good work brother. These are exactly the kind of videos UA-cam needs in such a sea of misinformation and click bait.
Also a suggestion-
Any interest in making a video or series about sleeping bags and warmth ratings? I know there's a lot of confusion out there about advertised temperature ratings versus real ratings. I figured you would be just the kind of guy to give a well thought out, researched and detailed approach to the subject.
Cheers,
Lou
I’ve been thinking about how different items come together to form your entire sleep environment from your shelter to your sleep clothes to the bag and pad. Also, the idea of bag liners (both inside and/or outside) for a layered approach. I’ll have to put it on the list! Thanks!
Anecdotally being one thru hiker with more than 6000 miles I have never gotten LaGuardia 😂 on my AT NoBo thru hike I started calling it LaGuardia. I even let some folks think I thought that was the actual name and it entertained me to no end. I used polarpure never ending iodine treatment that trip. On the PCT I used aqua Mira drops. Hikers around me did get sick and I noticed most of them didn’t take care of basic their hygiene. Dirty ol dirt bag hikers. Anyway I thought you might enjoy my personal experience with this. I’m also a wilderness guide, WFR, and a Master naturalist. Love the video! 👍👍
Thanks!
A lot of the studies I referenced also made the point about hiker hygiene, suggesting that some of what gets blamed on the water really comes from unwashed hands. Don’t reach into someone else’s trail mix! 😉
@@GearSkeptic you read my mind. I thought you might have the same ideas about that. I’ve preached pouring snacks into hands if sharing and have gotten sneered at lol. My wife and I don’t even reach into shared snacks or food. Really appreciate all the work you put into these videos…. The hiker food videos are also top notch.
I use a millbank bag to pre filter when the water is dirty. A sawyer squeeze and aquatabs. If one fails or i some how contaminated the water theres a backup to inshore i don't get sick. And it helps me sleep better at night. To back flush i put 2 aquatabs in a bottle let sit about 45 minutes. And back flush wile tapping the filter until the water is clear. Remember to always tap your filters when cleaning. It makes a world of difference. Ps. Thank you for all your very helpful videos.
My autistic brain that is prone to hyperfixation and going down the rabbit hole for my special interests loves your videos.Thanks for sharing this valuable content with your audience. You must be protected at all costs.
Are you me?
This!
Thankful for the risk reduction afforded by the sawyer filters over the last decade of outdoor adventure! I switched from the mini to the squeeze about 9 years ago for the flow rate benefit like you mention. Glad to see sawyer ranking at the top of these comparisons and that they most openly share lab testing. Great video series!
This is backpacker's college. Love the way you break everything down. Reminds me of my analytical classes I've taken.
Everything in this channel is highly brilliant. Hands only produces a recognizable tone. Info is well researched. Humour is intelligent.
Thank you very much!
I started backpacking in the 70s and for about 20 years I never filtered my water. I never got Ill. Then I purchased an MSR pump filter. It was heavy but did the job. As I aged lighter gear has become more important so for about 10 years I used chemicals and I also had no issues. I now use a Sawyer and it’s been good. No issues. For now I am happy. If I was doing something like the PCT I would bring my Sawyer and chemicals. I would filter then treat it. I must add most of my trips take place in the White Mountains of NH and the water sources seem pretty clean. Probably better than the crap from my home tap. Good video, thanks
Every one of the GearSkeptic videos is a masterpiece.
Thank you very much! Most kind 😀
WOW !
I am again in awe of your multiple series of my 'bible' chapters ... ultralight calories, water filtration ...
Thanks much!
I've been waiting for this video in particular as I prefer to filter. And after watching, am (mostly) content with my Sawyer Squeeze and Katadyn BeFree filters, though might go with the combined approach in certain circumstances. Thanks for all the time and work you put into your videos! It allows me to save my own many nerdy calculations and much research time for my gardening projects or the occasional acquisition of new gear.
I’m very glad to help!
I was excited when I looked at my phone during the Superb Owl game and saw that you had published a video again! This is the kind of quality content I wish I could find on many other kinds of topics, and I'm glad you exist for hiking gear!
I wish everyone in this vertical of youtube had the quality and information you put into your videos. Delivery of the information is top notch as well. I could listen to you all day.
Very kind of you, and much appreciated!
Man you should have 1 million subscribers. Thank you for putting so much work into all your videos
Thank you! I appreciate that.
A couple years ago, I took my son and nephew on a 3 day backpacking trip. We only used a sawyer filter and gathered water from a fast flowing river. We used one filter with a large bladder to fill our water bottles. My nephew got giardia and had symptoms for over a month. My son and I were fine. Thanks for your work, chlorine dioxide now added to the treatment regime
Holy grail of clean water information!!!! Your work is amazing!
Thank you very much! I hope it can help!
Watching this video made me realize I'm not the only one going down these rabbit holes with gear (which is good news as I thought I was crazy). Great video in an even greater series! Thanks for putting out such good content
Thank you very much!
One thing I'm not understanding well is how these filters have much lower log numbers for cysts, which are bigger, than bacteria, which are tiny. How are cysts getting through holes that stop almost all bacteria? Thank you for the incredible series of videos!
It's a good question that I've never seen addressed. One possibility that occurs to me is the effect of "testing only to the standard".
I've noticed that some tests only use an influent water with a concentration to match the log removal they are looking for. They finish with results of "zero" microbes after filtering. In this case, the test wouldn't reveal if the filter can actually do better than that.
Thru-hiker here- Sawyer (regular) with a 1.5 liter Cnog bag is the best setup. * Good review here
All I can do is express gratitude and appreciation for your content. Fantastic. Thanks again.
Much appreciated! Sincerely.
Fantastic Series you are putting together. I really enjoy the academic and analytical perspective you bring to the topic!
Man do I appreciate this video I actually felt like I got a solid answers not just more information, I’m greatfull
Thanks! I am very glad to help.
I love these videos! My already existing skepticism has been magnified greatly after watching your videos. I'm looking forward to sharing my newly found knowledge with fellow PCT hikers this season.
What a great video! As a former user of the Sawyer Mini the flow rate was unbearable and I would often find myself not using the filter because it was so annoying. Bought the Platypus Quickdraw filter and the difference is like night and day, I almost enjoy using the filter now! Even if the filtration is not as effective atleast I am now filtering the water I drink every time. Don't know about the longevity of the filter yet though, havent used it too much yet.
Haven’t had a chance to use mine yet. Anecdotally, I’ve seen other channels report higher initial flow rate in comparison, but then dropping off faster. Once I figure out a good way to test, I will do a follow up video.
I found your channel about 2 weeks ago from the prepaid airmen and I love the content, immediately subscribed.
Thank you.
Awesome! Thanks!
Thank you so much for putting out these videos for us, your work goes above and beyond, so detailed and informative. I’ve got pages and pages of notes from watching your nutrition for hikers series and it’s been really helpful for me, it was like taking a short course!
Always look forward to your videos and never thought I’d be excited to see a part 3 to a water treatment video series but here I am! I look forward to part 4 :)
Thanks, and you’re very welcome! I’m very glad to help.
Outstanding level of detail and commitment to real world evaluation. Thank you!
Thanks much!
Wow, that's such surprising information about the water from the campground faucet being the highest concentration. That's where i normally fill up. Interesting info!!!
This is seriously a great piece of work. Thanks so much! PS: Im glad my sawyer stands out well in your testing :)
Have you though of making these available as podcasts? 95% great to listen to on trail, even without the visuals!
I don’t know anything about podcasts, but some have commented that they use some sort of app to create a podcast from the UA-cam audio.
I just found your channel today and I'm hooked. This is the kind of research that's very valuable and entertaining at the same time.
Thanks! Hopefully some of it can be useful!
I live in north eastern Nebraska…agriculture and animal husbandry w/cow feed lots abound. I use a water filter as a pre filter then use a water purifier as a final. That way the filter saves my purifier filter and I get higher water volume out of it. Also, I disinfect both filters’ intakes and wash my hands. I back flush as well. Each filter (pump and gravity) is stored in its own carry bag. I’m retired military and a lifelong outdoors gal and saw early on how failure to follow personal hygiene in the field can lead to misery. It only takes a few minutes to filter, wash and store the water filtration systems needed for an outing. Proper waste disposal is required as well. Complacency and laziness are all too common out there.
Wow, really enjoying the series. It’s a master class on water purification.
Thanks! I hope it can help,
I'll be honest I didn't watch the whole thing, so I may have missed it, but one important factor to consider is being able to check the integrity of your filter and whether it is still filtering correctly. One of the reasons why I selected the Katadyn BeFree over the Sawyer was because you can blow into it as a test to see if the filter is still good or not. Not sure how good of a test this is, but this is what Katadyn says to do and it does give me more confidence when using it to know that it is still filtering correctly.
A fair point! I didn’t address that, so thanks!
Big thanks for putting this together...this is a huge help (Pass the Decimal on da left hand side!!)
Truely masterful research, analysis and interpretation. A sincere thank you for the time that goes make to produce these videos. A lot of information to take on board, but I'm very much enjoying the process.
Thanks! I really do appreciate that.
Very interesting series you have going here. I'm very interested to see your take on Steripen. Efficacy of the Steripen looks good on the surface, but you really dig into the details and I'd love to learn what you uncover. One thing that I frequently see mentioned, but never quantified, is that UV sterilizes rather than kills and that some pathogens can reactivate after a period of time. I've never been able to find any indication on how long that might be and to what degree.
I'm also wondering if you've done any looking at small micron monofilament nylon mesh filter bags. 25 micron bags are relatively easy to source and have great flow rates. Smaller micron bags are available, but a bit tougher to source and based on my experience with both 75 micron and 25 micron bags, I would expect affect on the flow rate to be noticeable at much below 25 micron. It just so happens that 25 microns is small enough to filter out some of the larger unfriendly bugs (some protozoan cysts, for example) and does a great job of removing particulate that might otherwise hide the bugs from the UV light. We've been using a 25 micron bag for the last few years as a particulate pre-filter for a Steripen while hoping that we were also gaining some level of purification help as well. Either way, they do a great job of removing the wonderful floaties in the water and they are super light at around 4g for the one we use.
Regarding your comment at the end about using a filter more than once on the same batch of water to increase effectiveness, I have to wonder why some of the harmful critters made it through the first pass. I'm actually quite curious why the filter process isn't more pass/fail. Is it because any bugs larger than the filter pores fail to make it through, but ones that are the runts of the litter fly right through with no problem? If that is the case, I would expect the second pass through the filter to accomplish very little. Is it instead because the filter has a small number of "defects" where the pore size is either larger than expected or a failure in the medium causes that same effect? In that case, multiple passes through the filter might result the same percentage of pathogens taking the freeway each time, but with the overall population reduced on each pass. That might also explain why the filter fails to filter the larger pathogens at 100%.
The Sawyer datasheet you included suggests the former as they seem to claim the latter is not possible. They go as far as to say "No harmful bacteria, protozoa, or cysts can pass through the SawyerPointOne Filter" and that "No pore is larger than 0.1 in the Sawyer PointOneFilter." If the largest pore size is 0.1 micron (μm), how on earth do we have these little guys making it through? From en.wikipedia.org/wiki/Bacillus_subtilis, "B. subtilis cells are typically rod-shaped, and are about 4-10 micrometers (μm) long and 0.25-1.0 μm in diameter". www.ncbi.nlm.nih.gov/pmc/articles/PMC8123537/ indicates the size of R. terrigena to be 1-2 micron. www.tandfonline.com/doi/pdf/10.1080/23311932.2019.1569830 says it's "cell shape was short rod, with cell length of ... 1.60 ± 0.08 μm." Unfortunately, they don't give a diameter, but a photo of a slide from the first article suggests the rods to be maybe 2-3 times as long as they are wide. That would put the low end of diameter at about 0.51 micron. M. luteus also seems to have a size of around 0.5 micron. That's at least a full 5 times larger for the last two than what the Sawyer should "Absolute"ly filter out. Something has to give since a few of the bugs are still making it through. I wonder what it is?
Very interesting ideas! I’m always inclined to say that it’s not restricted to just one option. All those things might be going on simultaneously:
No manufacturing process is perfect. Hole size will vary.
Living things aren’t exactly alike. Some will be bigger or smaller than the average.
Nothing is ever perfectly ordered. They way in which irregularly-shaped organisms address the filter media will differ.
I would expect all of these things on your excellent list to contribute to less-than-perfect results.
Let me add another: cells aren’t immaculately rigid. Consider a basket full of water balloons. The balloons might not fall through the holes of the basket under simple gravity. But, push on a squishy balloon hard enough and you might force some through.
I wonder about the role of pressure and the rate of pass-through for microbial threats…every time I see somebody squeezing the bag on their filter system so hard it pops.
Seconded on the question of the steripen. Going on the two is one and one is none, steripen is an attractive backup system
Another excellent presentation. I’m really enjoying them. Thank you.
Sweeeeeet! The best water videos I've ever seen!
Thanks! I hope it doesn’t disappoint.
Okay, I'm a believer now. Well done, as usual!!
Always a treat to watch one of your videos
Thanks!
Thank you very much for your nice review, I love it... But, us I am another "skeptical", in this peer review context that UA-cam provides, here it is what I missed: when speaking about filtration "size matters". Reduction provided by hollow fiber filters depends both on the average size of the tiny pores that this hollow fibers have and in the size of the particles that you are intending to eliminate from the water. In this case in the size of the bacteria, protozoa and viruses. Obviously viruses are too small to be retained by the filters, so they are out of the equation. Eukaryotic protozoa cells are much bigger than bacteria cells. So, if a filter claims a reduction of six logs for bacteria, expected reduction for protozoa should be much bigger. IMO, filtering is a safe option for protozoa risk and for bacteria in most circumstances. For worse scenario, combination of filtering first and chemical treatment second would provide a enough safety level. I'm not sure if filtering twice would provide the same safety level: bacteria small enough to pass the pores the first filtration would be able to pas it again in a second filtration. I know that there are other factors influencing this, like distribution of pore size, so more investigation on this would be needed.
Good points!
My sawyer squeeze got really drippy and slow in the offseason, and my treatment was: backflush with water and vinegar, soak in warm vinegar water for 1-2 hours, the a half dozen hard backflushes with warm water and it was flowing like new again. I did use the syringe, i use the bottle method in the field(with a squeeze bag).
Thank you for that educational video!
You are most welcome!
Thanks for this extremely useful video. I was made aware of you by one of my viewers, as I'm addressing water filters right now. I learned a lot. Thanks again and will be watching the other videos as well of course !
Awesome, and thanks much!
Love this series!
Another amazing video on a very important topic. Thank you. I really hope you include a section on UV purifiers in one of your future films.
I will! Working on virus filters next, but also gathering research on UV.
Excellent series. Valuable. Thanks!
Amazing series! We need more people like you. Maybe some of the science channels would be interested in a partnership or something like that.
Thank you! That is very kind of you to say.
Great to see another video from you my friend! Your content is always absolutely excellent, thank you so much for your work and your contributions to this field :))
Thank very much! Always appreciated.
Another superb video. I use a pair of Sawyers daisy chained one directly above the other, exactly for the function you mention at the end!
Timeless work here! A related topic for a guy with admirable patience and curiosity - what happens to these filters when they freeze? I've heard of catastrophic housing failures as well as subtle leaks in the hollow fibers. Some vendors say there is simply no way to test a filter for subtle harm after a freezing event, while others suggest blowing air back through at modest pressure can identify microleaks. (Sawyer claims to test each filter three times during manufacturing. How do they do that?) How hard of a freeze is required to cause a problem? Are all filters equally susceptible? Is there a way to anti-freeze your filter other than keeping it in your sleeping bag? Thanks again for a really informative and enjoyable video!
Very informative I’ve been looking for a good source of info like this for a long time.thanks very much appreciate your time and effort.😊☮️
Always glad to help!
Loved your hands in this one.
🤚🏼🤌🏼👍🏼 😉
I carry a BeFree and a Sawyer mini. The BeFree is terrible with dirty water, I prefer to use it on canoe trips when I can scoop "clean" water from the middle of a lake. Once at camp the Sawyer gets setup on a ridge line with a larger feed bag.
this is another great instalment in your water treatment series. i wonder if it would be possible to mention the best ways of eliminating as much as possible crop chemicals or heavy metals in water supplies that may fall foul of agricultural run-off. thank you again for analysis
Definitely! I’m gathering research on adsorption filters and activated carbon for another video. Those technologies will reduce chemicals and heavy metals.
thank you! did i miss where you gave data on the sawyer squeeze? you refer to it constantly, but every time you get into specifics, you only use the mini (but i could have missed!). where does the squeeze sit in your comparison/analysis?
It has the same filtration rates as the mini. Both use Sawyer’s “absolute 0.1 micron” fibers. The Squeeze has a better flow rate, though. I aim to test that in the future.
Excellent information. Somewhere in the gear room, I have a bottle of flocculant concentrate meant for really muddy water, but I don't know much about using it. Might make for good content. My experience with all three Saywers and the Befree is that you will essentially need to replace the filter every 1.5-2ish years if you're a weekend warrior hiker doing 10-20 trips a year. YMMV but I notice no difference between them in service life before they get so agonizingly slow, you can't use or clean them any longer. For pre-filters, I've seen two pretty interesting if fiddly bits. Millbank bags seem to be a British army thing and let you pre-filter solids from the water. I've spoken to someone who swore by using filters meant for making biodiesel. Not a clue if they are safe for drinking water, but they appear to come in fairly fine mesh sizes. I always wondered if I could combine the two products. I purchased something that looks a bit like a condom that goes over the stem of my Befree on Amazon, it didn't end up working with my hydrapak soft bottles so I've never been able to use it.
I am currently building quite a collection of pre-filters. Everything from coffee filters to micron-level meshes and screens. That’s hopefully a future video.
You can buy millbank bags for drinking water. They are popular with bushcrafters.
I’m also curious about flocculants. Thanks for the reminder!
@@GearSkeptic After much head-scratching, I figured out the flocculant I purchased was an impulse buy after watching "De-silting water treatment for ultralight backpackers" on Jim Pflugrath's channel. It appears to be something other than plain alum which is interesting, but I don't know how the performance compares. I also see Rothco Chlor-Floc on Amazon which sounds interesting and contains a super-secret flocculant with sodium dichloro-isocyanurate. My thought has always been to re-package into a tiny dropper in case a torrential rain turns the stream's super silty. I generally don't have issues with turbidity in the mountains. Protecting the filter from tannins in the water in places like Dolly Sods or the BWCA would be more of a concern.
Thanks so much. Very comprehensive, useful info as always.
I appreciate you saying so, and very glad if it can help!
Might I suggest a vid on silt removal via coagulation?… … it’s an advanced for topic for backpacking, common for rafting rivers, and used ~every minute in ~every water treatment plant worldwide. I suggest comparing the classic flocculant alum to modern polymers.
Will do! There’s probably going to have to be Parts 5 and 6 (UV light is another requested topic).
Excellent video!
Are you an engineer or biologist because I love this methodology and it ain't on UA-cam enough!!
I'm not, but thanks! :)
You dropped this, 👑
😬
My interpretation is that Gentry Austin is telling you to pick up your crown because you are the King when it comes to the most thoroughly researched and comprehensively presented videos containing extremely useful information on You Tube. Thanks so much for what you have done and continue to do. Martin.
Yeah... I'm waiting for this 😘🥳🎉 thank you 😘😘😘😘 greetings from Taiwan 🙋🏼♂️🌴
Greetings!
Thank you so much, for your work!!!
This is freaking fabulous!!
Thanks much!
Don't know if you have plans for a part 4 but how about covering flocculating agents? Love your work!
I think Part 4 will be virus filters, but I’m also looking into flocculants, activated carbon, UV, and options for pre-filters. 👍🏼
Love your videos. Thank you for your time and energy! Was also curious about the you make chlorine filters by using salt and electricity. Snd of course uvb filters. Also wondering if leaving your filtered water sitting in direct sunlight how well microorganisms are reduced.
Thanks!
I have begun research on both UV pens and solar methods for disinfection. Future videos in this series to come!
For the salt/electricity methods (like Miox), it's a novel way to get it, but you basically end up with active chlorine as your disinfectant. If you check out the Part 2 video, there's a description of chlorine vs. other chemicals.
Great video like always.
Thanks! I appreciate that.
After seeing that hilariously high contamination straight from a faucet; I feel much better about always, regardless of source, filtering through my sawyer.
Big Steripen fan here. I would love to see a comparison of Steripen to Sawyer. I'm just afraid my sawyer squeeze will clog and I won't have any clean water to backflush with. Of course my Steripen could also malfunction.
After watching your videos, I'm getting some ClO2 tabs to replace the iodine tabs for a backup.
Yes! Working on a UV and solar disinfection video, too. Virus filters next, but maybe in Part 5?
I can feel it already before finishing this. I’ll go from almost paranoid to extremely paranoid off the charts.
I like to think of it as “controlled paranoia”. 😁
Odd question referring to your rough math at 37:00 to 37:30.
If a CFU consisting of 10 cells were to enter a filter, wouldn't that make it easier for the filter to catch it just on size alone?
I guess this entirely depends on how well the cells stick together, or if they easily separate once they reach the filter.
This is something that I know literally nothing about(as you can probably tell).
Also just want to add this isn't antagonistic, just genuinely curious. Your channel and every one of your videos are amazing and have made my backpacking experiences significantly more enjoyable. truly can't thank you enough.
I think CFUs are something that result from growing microbes artificially in a Petri dish. I’m not sure how well that would translate to the wild. I have read that some things like viruses may not be primarily loose as individuals in backcountry waters. They can tend to cling to larger particles of debris. That could certainly help with their filtration. Real world vs lab gets complicated.
I was looking at using a Sawyer SP160 and after looking at some rather disgusting throughput I found the Katadyn Steripen (sediment) Pre-Filter which will fit on the Sawyers input opening. This, I hope, increases use, longevity, clarity and reduce backflush requirement.
Interesting! I did not realize the fit together. I will have to try that. Thanks!
@@GearSkeptic Going on what I've seen, not personally tried: The Steripen fits in a Nalgene filler - which, apparently, is the same size as the Sawyer SP160 inlet.
Fantastic contents. ❤
50:20
Did I understand this right?
The Sawyers have the same fibers. And the squeeze filters faster because he has more fibers?
I thought if water has to run through more fibers it would flow slower.
Or does this mean the squeeze has more volume too and that would reduce the density of the fibers?
Very good channel and very logic and scientific approach👍🏿❤️
Yes. More fibers for more volume passed. In terms of, say, a garden hose: it is like having two hoses running side by side (not connected end to end).
@@GearSkeptic I understand. Thank you!
What were the odds that I would discover such a research heavy channel with such interesting topics right as I start getting into backpacking. I'd say around 5 log
With luck like that, you ALMOST don't need to carry a filter!
Incredible research. Much respect. One of the complaints that I have seen over many videos is on the CDT where there are stretches of areas that lack water and the sources of water that they do come across even after using many of the filters presented here, is the awefull taste that remains. I imagine that is probably due to the mineral content remaining. Can you address that issue in your research? I am not a chemist so I don't know the size of certain minerals vs pathogens but I would imagine the pathogens are much smaller. So why would you have the aftertaste after using these filters ? Is this some sort of solubility/chemical difference? Wouldn't the minerals be filters out or is that a different type of filter that must be used (e.g. carbon filter)? Have you tried any filters that add the additional feature of aftertaste/mineral removal?
One of the response to this other author's prefiltering sediment is that his method cannot remove Tannins. I am not sure what Tannins are chemically but I guess it comes from trees etc.. Are these contaminants harmful to drink?
ua-cam.com/video/udzGUXi_gzA/v-deo.html
The Meltdownman
Tannins: ua-cam.com/video/-F-M8yGX5JY/v-deo.html
Chemicals, dissolved minerals and heavy metals are all very much smaller than pathogens. They go right through a conventional filter.
You need activated carbon to remove them, which works by an electrochemical process of adsorption. I am working on that research for the Part 4, because adsorption is also used for viruses. Stay tuned!
Hi! Just trying to remember which Sawyer filter you preferred over the others? Was it the mini? Thanks! Deeply love all of your videos
I prefer the mini, though people on long hikes tend to end up with a Squeeze (faster flow, filters for longer before clogging, but bigger and heavier). They should all have the same filtration.
@@GearSkeptic perfect thanks! I have only used the mini but don't find the flow rate much of an issue. Thanks for getting back to me, really love your videos!
Fantastic video! Thanks so much! Question: I hike a lot in Europe and most of the hikes I go on have 3 types of water sources. 1) water springs where pipes come out directly out of the ground; 2) cattle/sheep/goat water trough 3) rivers and streams (some fast most moving some slow, some in high elevations some in low, some with in areas with some animal husbandry (cattle, sheep and goats) and other without; I would love to know the concentration of pathogens in these types of environments (particularly 1 and 2). If springs are really clean (as I've been told) presumably I could get by with much less Log protection. Similarly, in the water trough I've seen, I assume the animals do not crap in it (I could be wrong) but put their mouth in it. That being the case, I wonder how much are the pathogen concentrations in this water source type (and what filtration protection I could get by at. BTW, in the last cast I had always used the chloride dioxide tables too (but sort of by chance since I was too grossed out by the water). Your last video on chemical filtration vindicated my hunch (thanks again). Also, these series highlighted the invisible risk of swimming in watering holes that I've seen many hikers jump into (and I've often wanted to as well but mostly don't actually do - particularly still waters).
Check out Part 4 on Ultrafiltration. It goes into the risk of viruses in various types of places, and Part 5 gets further into stuff like the issues with water runoff from farms. Hope that helps!
Questions: 1) Do Squeeze and Mini have identical pathogen removal rates? 2) Dual filters being more realistic than re-filtering a second time, how does Hydroblu-->Mini compare to Mini-->Mini? Surely, the "logs" don't simply add (Hydroblu's 3-log + Mini's 7-log ≠ 10-log?)? Whole-house filters always place filters in descending micron order, 50u-->20u-->10u-->5u for example? Perhaps Hydroblu-->Squeeze for reasonable flow-rate?
I believe Squeeze and Mini have the same filtration rates. They use the same “absolute 0.1 micron” fibers. Squeeze just has more so it can flow faster and take longer to fill up.
The question of whether logs of removal simply add is an interesting one that might depend upon why the filter is missing some microbes. If it misses mostly because some few of the fiber holes are too big, I think the logs add. You run the water through again and chances are those microbes that escaped won’t encounter a big hole this time. Those “chances” being the actual filter percent.
But, suppose the misses are due to some microbes being smaller than the rest. Smaller, in fact, than the average hole. In that case, it might make little difference to filter a second time, as those little microbes would just make it through again.
The reality might be a bit of both, where you get a good amount of additional removal, but not fully like just adding the logs together. I wish I could find some lab tests on that!
Mini to Mini should be better than Mini to Hydroblu in any event. I’d put the lower rated filter in front, as it is more like a pre-filter to help prevent clogging of your finest filter. Redundancy in the event of a field failure is never a bad idea.
As usual, great video series!
Ignorant question here: Do these filters aid at filtering major particles like say for example a mountain river with lots of sediments in suspension? Is the efficiency reduced?
Yes, to both. They do a great job at making muddy water clear. But, dirty water like that will clog them faster, so backflush more often.
once again an excellent video, please take the steripen for your next episode ( virus). there is no profound information about this either, except for the advertising statements.
Interesting and wonder if you came across this question being addressed in the literature. How long can giardia parasites remain active in your gut and if it was say 9 days as you mentioned it can take to feel its effect, could it be cumulative and using a filter that has a log 7 filtering ability and only a very small amount got through each day and you drank different sources that this happened, would it be the same as just drinking out of one source with a lower log value of purification at once?
Interesting question. I didn’t read anything on that, but I’d assume that dose can be cumulative, at least over the incubation period.
Part 3! Niiiiiice