Feb 20, 2007 at 2:22 pm #1221949
I've shaved my base pack weight down to 9.54lbs, something I'm very proud of…but one heavy device stands out. My one pound MSR Miniworks EX. Maybe its lack of use, but I'm very leary of chemical treatment of water. Not because of health concerns, I've read some of the great articles here about it, but more because of debris concerns. Last trip I did here in GA, all the water sources were small streams with lots of debris and I was so frustrated with my Steripen "Pre-Filter" the whole thing ended up in the corner of my closet. I used my friend's pump filter for the remainder of the trip. Can I get some advice as far as how everyone handles it? Do you use inline filters, just use a bandana over your water bottle then drop chemical in? Thanks in advance.Feb 20, 2007 at 2:35 pm #1379355
@garkjrLocale: Southwestern Ohio
I'm in a state of flux right now. Six months ago, I was packing light, with a base weight around 14 pounds – which included an MSR Miniworks filter. I've never had the first problem with it.
I've now acquired a TarpTent Rainbow and a new interest in trying to make the "ultralight" cut to 10 pounds. I'm pretty well there, and the Miniworks is, for now, in the spare gear bin. It's been replaced by a Katadyn Mini Filter, which weighs only 8 ounces. I've not had any problems with it so far. Like the Miniworks, it's a ceramic filter that is field-cleanable (a feature I value, since the paper-element filters I've tried clog too quickly and add weight to the pack because I find myself always bringing a spare element.) The Mini does take a bit more effort to pump, and takes about a third longer to fill a liter bottle. But, for the weight saving, I've found the extra couple of minutes worth it – besides, is 10 minutes extra in my backcountry schedule really going to ruin the trip?
One thing I'd suggest to make the Mini easier to use: if you aren't already, use a Platypus bottle. You can buy a Platy Link (sold by REI and BackcountryGear – though at BCG, you'll find it on the page with Platy bottle caps, for some reason.) Attach the Platy Link to the output hose of your filter, shorten that hose to suit (I only leave enough to secure the link to the filter), and you've now got a way to screw the bottle to the filter and come close to the convenience of the Miniworks. (I've never looked for a similar adapter for Nalgene bottles.)Feb 20, 2007 at 2:35 pm #1379356
@ling_jdLocale: columbus ohio
great question! I often wonder the same thing.
I've found that bandana's deflect a lot of water when trying to fill a bladder. this might work better with a wide mouth container, but mine is bottle-cap size.
so now, I fill my cook pot in the stream and pour the water through my french press screen (used with my jetboil system), and that seemed to clear a good amount of the big stuff out. then i zapped it with aqua mira.
I'm curious, though, to hear how other people do it. especially considering how i'm thinking of giving up the jetboil for an alcohol stove.Feb 20, 2007 at 3:04 pm #1379359
@gfinley001Locale: SF Bay Area
One technique I use for water with lots of "floaties" is to stretch some mesh from women's hose over the opening to the water container. This works better with wide-mouthed containers, but it's almost weightless and will filter out most of the visible material. Obviously won't work for water with solids in suspension (e.g. glacial run off).Feb 21, 2007 at 1:18 am #1379425
@bigrgLocale: Snowy Mountains
I have the same worries about water . What I am going to try is a "Brita" waterbottle with filter plus the new steripen adventure model . The waterbottle is 100 gm and gets rid of "floaties" very well . Then I would just pen it and be ready to go .Feb 21, 2007 at 1:35 am #1379426
Richard, I'm not sure of how the Brita-bott works. If the filter is an effluent filter, meaning that as one drinks the water gets filtered, then i probably (more on "probably" in just a bit) would *NOT* recommend its use with a UV-C filter. If, however, it is an influent filter which filters the water b/f it enters the bottle, then 'ok'.
For UV-C purification to work properly, the water needs to be clear (and not too cold, i.e. near freezing temps) so that no lil' nasties are able to hide from the light behide tiny "floaties" (clever lil' buggers, aren't they?!). So, the water needs to be pre-filtered b/f UV-C treatment, and not merely before drinking.
Proper order of treatment:
2. UV-C (or chems, for that matter)
If your Brita-bott will permit treatment in that simple two-step order, then go for it. Otherwise, think about another solution (which still may include the Brita-bott, but will add some type of pre-filtering on the water entering the Brita-bott). This approach probably has the added advantage that pre-filtering prepares the water for UV-C (or chemical) purification. The UV-C or chems kill a whole bunch of different types of lil' nasties. The final filtration stage as one drinks which is in some types of bottles will remove larger, rarely encountered intestinal parasites which are too large to be killed by either UV-C or chems at the dosage levels typically employed for either, but too small to be removed by some pre-filters.
Hope this info helps.Feb 21, 2007 at 3:10 am #1379429
Stephen, I use a coffee filter, then Katydin Micropur. If the water is snow runoff, or running crystal clear I don't bother with the coffee filter.
BUT, Something pj said about ringworm cysts not being killed by Micropur has been haunting me.. pj, is there a light weight way to get rid of those?Feb 21, 2007 at 5:30 am #1379434
Brett, i didn't specifically say ringworm (i'm thinking yours is a "typo" and you meant to say "roundworm"). I was thinking more of tapes & flukes, but any larger parasite, like nematodes would probably fall into the same category is my semi-educated guess.
[BTW, "ringworm" is NOT a type of "worm" – it's actually a fungus, NOT a roundworm – generally one of two species of dermatophyte fungi similar to that causing "Atheletes foot" & "jock rash/itch", etc.; BTW, Jewelweed aka Touch-me-Not, properly prepared, is a great natural remedy for "ringworm" as well as for poison ivy – works GREAT, IME]
As far as an UL solution, hmm…, YOUR coffee filter is pretty UL. Yes, it's Mfr'd w/an uncontrolled pore size, but supposedly your typical paper coffee filter has pores of varying sizes ranging from b/t 5-15 microns inclusive (that's why they filter so slowly!!). This should handle most (all???) of the lil' nasties not rendered lame or dead by UV-C or chems (at the normal L/UL backpacker dosing levels – higher levels can kill them, like ~24x to ~28x higher UV-C levels will eradicate ~98% of hydatid tape "eggs").
"No", a paper coffee filer is NOT too robust, so i don't recommend them for inline gravity (unless examined b/f each use) or on-demand inline filtration, but for prefiltering where its integrity can be examined (yeah, i know we'd need something like a stereoscopic dissecting microscope, or better, to see larger than the 25micron perforations that could allow tape eggs to pass), i'd, personally, go with it.
Unless one is in an indigenous area where these rare nasties are known to exist, it's generally considered something that one needn't worry about. Theoretically, though, they could be most anywhere certain types of host creatures are located (e.g. wild or feral canines & hydatid tapes).
The way i look at it is, if some of these rare nasties were that much of a problem (outside of KNOWN indigenous areas), we would already have a "TON", so to speak, of ANECDOTAL evidence from the medical problems of the many, many UL Thru-Hikers who don't treat for these nasties using normal pump filtration (more commonly used by heavier-wt backpackers). In other words, we'd have common knowledge shared by others who Thru-Hiked and said something like "50% of us are coming down with this…or that…clinical disorder/disease/illness, etc." Now, some of these may not show up right away, but i think by now, decades later that there would be some anecdotal evidence if this was a problem. Instead, what do we hear about?, viz. Giardia, Crypto, etc. – NOT flukes, tapes (other than indigenous areas, e.g. Isle Royale NP), roundworms, etc. Sure, unlike with smaller buggers, it might only take ONE ingested egg or [meta]cercariae (depending upon the parasite involved) to cause a problem (smaller buggers, e.g. bacteria & viruses, usually require a much larger "load" [a real term, not a "pj-ism"]). However, to my way of thinking, the fact that even ONE can cause a problem, only supports my reasoning that anecdotally we'd already "KNOW" that these larger, rare nasties are something we should be concerned about. By this i mean, generally "odds" are easier of encountering ONE rare occurence than a whole bunch of them.
Are these rantings clear? or, have i "muddied" the waters, so to speak?Feb 21, 2007 at 5:32 am #1379435
All very good points and these are the same ideas I've been struggling with. I'd rather not litter my intestine with sand and sterile animal dump, but then again out of sight out of mind I imagine. I really like the Steripen idea, but the prefilter they sent along with it was absolutely useless, we tried everything and were left wondering if it (prefilter) was just a gimmick. I guess a coffee filter and the steripen would've been a more light alternative.
Are small amounts of dirt/debris in your fluid containers the price to be paid for such a lightweight solution? Am I underestimating the effectiveness of something like a coffee filter?Feb 21, 2007 at 6:09 am #1379439
Generally, i'd say that you are underestimating the effectiveness of a paper coffee filter (i don't know the pore size of those fancy, smancy [or is that spelled s'mancy???] metal or gold ones) WHEN USED AS A PRE-FILTER.
Theoretically, and to some great degree practically, "small amounts of dirt/debris" (i.e. VISIBLE to the unaided eye debris) is NOT a good thing as it can harbor or shield some microorganisms from the effects of both chems and UV-C methods of purification.
The goal of PRE-FILTERING is to get the water visually clear to the unaided eye.
IME, paper coffee filters work well, but clog easily if the water has a lot of dirt or detritis floating in it, and are VERY slow, but given their relatively small pore size they work well as a pre-filter. Keep in mind that dissolved solids, miscible liquds/chemicals, solutions, are NOT filtered out by virtually any simple mechanical barrier filter, nor are viruses, no matter how small the pore size (even tenths of a micron pores). Also, colloidal suspensions of some types may not be [completely] filtered by a run-of-the-mill coffee filter. Larger suspended particles can be filtered with one though.Feb 21, 2007 at 9:41 am #1379475
I'm getting the feeling that this is a "reduce your chances" and hope for the best type situation in regards to weight. Ideally, one would carry a standard pumpstyle filter and a UV device, or a combination of pump/chemical… is this true? Surely, there's got to be a better way… are there not any effective reusable prefilter devices that are standard or can be counted on?Feb 21, 2007 at 10:23 am #1379485
You want positively, absolutely 100%?
Ignoring, undetected manufacturing defects (oops!, or is that "oopsie!"?), or in-field failures ("double oops!"), and also ignoring a number of non/semi-humorous "water treatment" replies that "pop" into my head at the moment, i'd say that a "practical" 100% could be acheived by…
filtration (pump or a good gravity filter) + chemicals
filtration (pump or a good gravity filter) + UV-C
a 2.0 micron (NOT 0.2micron), so-called "cyst" filter can be pretty light (relatively speaking).
chems are lighter than UV-C (up to a point on L-O-N-G resupplies, but then one might NOT reach that point with any
reasonable resupply interval).
Some items like the First Needs Pump (heavy), Katahdyn Purification Bottles (NOT the cheaper water filter bottles lacking the iodized gel anti-viral stage) [too little volume – though there are workarounds], and the Sawyer-Purifier claim to be a "Do-it-all" solution to the Backcountry Trekker's water purification needs. You might want to look into those for your 100%(???) solution.
Is a "practical" 100% worth 6oz or 8oz? An individual decision to be sure!
For me, knowing what i know (or is it "thinking i know what i don't really know"???), pre-filtering + UV-C (or chems) is fine even in the lower altitude, more relatively populated, agricultural areas that i am sometimes in.
NOW, we haven't begun talking unwanted chemicals yet!!! What to do about them? Activated charcoal? Works for some; not for others. Wonder if i have more risk of being struck by lightning? Wouldn't surprise me at all!!Feb 21, 2007 at 10:35 am #1379487
PJ, what are some examples of 2 micron (as opposed to .2 micron) cyst filters? This is exactly what I am looking for, since my primary concern is helminthes and their eggs. Actually 5 micron would be even better.
I tried using the Seychelle inline filter last year, but it seemed too much of a nuisance and I ended up chucking the thing after a week. Maybe I'm being unrealistic about ease of use since my standard procedure is simply to drink untreated water. (Occasionally I get a bit of diarrhea but it passes in a day or so. I think my immune system is pretty strong with respect to bacteria and giardia.) What I really want is something like the Katadyn Hiker Pro with a 5-10 micron durable and field cleanable stainless steel filter. Gravity and inline filters just seem much too slow. When it's near freezing, I don't like standing around fiddling with things with wet hands, so I want a pump to speed things up.Feb 21, 2007 at 10:45 am #1379489
the following suggestions still will require (if you feel you need to) treating with chems or UV-C to kill small protozoans, cysts, bacteria, and viruses.
General Ecology Microlite filter
~7.0 oz , slow pump rate, 1.0 micron absolute pore size [but we can use it for the final possible solution to your particular water purification requirements]
I was also thinking of the Seychelle when I wrote my prev. Post, but you've already tried that one.
Also, look for so-called "silt" filters with a 20.0 micron absolute pore size: Sweetwater Silt Stopper (~1.0oz) it was called, IIRC. It might be another one i'm thinking of as i've also seen the Sweetwater listed as having a 5.0 micron absolute pore size (THAT'S RIGHT IN THE RANGE YOU MENTIONED).
AquaMira actually makes a ~23oz (i forget) water bottle with an effluent on-demand filter element. The filter is sold separately as replacments. It is a 2micron (IIRC) "cyst" filter, but you might need to put on the "thinking cap" b/c it has a funny shape that might be difficult to "plumb" into a system.
There are other water filter bottles also with cyst filter (generally around the 2.0 microns size) that might work.
Katadyn makes cyst filters for their ExStream system. It is NOT a sub-micron filter like in their pumps. Perhaps this could be "plumbed" into in a gravity filter and since the pore size is larger, the water should filter through at a higher rate. Not exactly what you're looking for, but an improvement over your prev. grav. filter experiences.
A heavier, but higher forced (think "pump" here) flow rate solution would be any filter with a 20micron or smaller SILT-FILTER attachment on the end of the influent hose. Remove the real filter element (lightening it a bit) and making pumping faster and easier – chems or UV-C is req'd to kill smaller nasties that get past the 20micron siltfilter.
I'm thinking that if you took the smallest, lightest PUMP FILTER you could find (about 7oz) even though it doesn't have a siltfilter attached to the inlet hose, DITCHED the internal sub-micron filter (lightening it up a bit), "plumbed in" (perhaps even internally since the sub-micron filter is now removed – if not, then it would be easy to attach inline with the effluent tubing) the 5micron Sweetwater filter (Crypto, bacteria, and viruses could still get past the 5micron filter), and then treated the effluent PUMP pre-filtered water with UV-C or chems, that might work – maybe that would work for you?
I might try this last suggestion myself. Another way a pump is sometimes helpful is when the water source is so small that it's difficult to dip anything in it to gather water, but the inlet hose of a pump fits just fine.
Starting with a 7 or 8 oz. pump filter, remove the filter elements (must save some oz, maybe even 1/2 the wt if it's ceramic – some larger ceramic elements are as heavy as 4oz), add in a 1oz Sweetwater siltstopper, shorten the inlet and outlet house a bit (to "shave" some grams off). Could it be only 4-5 oz??? Don't know. Remember, it won't remove protozoans, cysts, bacteria, or viruses.Feb 21, 2007 at 12:05 pm #1379499
Thanks for all the great replies…that'd be quite a frankenstein water system pj but interesting nonetheless…
I guess in making the transition from pump to chemical treatment I really just want to know how everyone handles it. Like you pj, how do you personally deal with it?Feb 21, 2007 at 12:54 pm #1379511
todd harperBPL Member
@funnymoLocale: Sunshine State
I, personally, don't care for chemicals so I recently switched to the Steripen Adventurer.
For a prefilter I use a coffee filter (Although the pantyhose sounds more durable). Here's how I deal with the prefilter issue:
I create a "funnel" shape w/the coffee filter and set it into the zippered opening of a 2L Platypus zip w/handles. I prefilter one liter into the platy using a cutoff worn-out Platy which I cut the top off of (makes scooping from shallow streams a breeze), then zap it w/my Steripen. I can then fill my gatorade bottles via the pour spout of the Platy. Works great and the whole setup weighs a good bit less than a Miniworks or similar. I hope all that makes sense!! Yet another plus is I can fill my bottles and still store 2L in the Platy for cooking, etc.
Assuming the UV actually works, I'm pleased:)Feb 21, 2007 at 1:28 pm #1379517
My approach varies depending upon which purification method i happen to be "playing with"/using on a particular weekend trek.
1. prefilter water through a bandana into a soft-sided, large mouth, Nalgene Cantene – it's clear, so now onto step #2 [no real, legitimate, pressing concern about larger parasites in this water source, just pre-filtering to make sure chems work properly]
2. AqM – chemical treatment since the water was most likely too cold for the UV-C unit to work properly. Otherwise, in warmer weather, i am more often using UV-C in place of AqM due, primarily, to the, essentially, "no wait" factor.Feb 21, 2007 at 3:53 pm #1379539
I've considered some of the same ideas as you. The problem with the Siltstopper is that it is not field-cleanable. It's basically just a roll of filter paper. When it clogs, you are supposed to replace it. My problem is that I will be traveling and unable to find replacements. I could carry a whole mess of replacements, of course.
The "plumbing" you refer to would involve some sort of seam sealing with silicone or whatever. I'm sure this could be made to work, but I just know I'll screw up the first few times and won't be able to make fixes until I return home. So it might take years before I get a system perfected at the rate of one experiements per year.
I examined a Katadyn Extream water bottle filter to see if I could remove some of the pieces, but no, the cyst-filter isn't sized right to work alone. You have to have all the parts together.
The various steel pre-filters are typically in the range of 40 microns and up. This will screen most adult helminthes that can infect humans, but I'm not sure it will screen their eggs.
The ideal filter for my purposes would consist of a series of stainless steel meshes, starting with a coarse (100 micron or so) filter at the end of the inlet tube and then several disks in series inside he pump body with a final mesh opening of under 5 microns, which I believe is possible with steel mesh (http://www.smallparts.com/products/descriptions/2030.cfm). There would be a pump to speed up the filtering and a provision for backflushing to clean all these filter elements. Such a filter would clear out the helminthes, which is all I'm really worried about.
Then again, maybe I'm just worrying too much. Life expectancies among shepherds in Greece and Turkey, which is where I'm most worried about the possibility of helminthes, is not known to be particularly short, and I'm sure those shepherds just drink the water untreated. I know for a fact that all this hysteria over giardia and ordinary bacteria is just that–hysteria–unless you have a compromised immune system. The problem is that there money to be made exploiting this hysteria, and apparently no limit to the amount of gullible people who fall prey to this hysteria.Feb 21, 2007 at 4:13 pm #1379545
Frank, the problem you're attempting to solve is very interesting. i'll keep my eyes open as i surf & read. if i come across anything that might be viable, i'll Post it here in the Forums. Sorry, i couldn't be more help.Feb 21, 2007 at 5:44 pm #1379561
Jason SmithBPL Member
Currently I am using a nylon monofilament mesh bag as a prefilter. It is around 20 microns if I remember correctly. I have seen them with smaller mesh as well, down to 1 micron. I dont know how reliably they maintain there size. Maybe something for BPL to research and stock stock. Im planning on reseaching them more this summer when I have time.
Here is a siteFeb 21, 2007 at 6:36 pm #1379573
Jason, these nylon mesh bags look extremely interesting, especially the 5 micro size. I'm going to call these people tomorrow. But I'd be interested in a lightweight backpackers's perspective as well:
How much do the bags weigh?
How durable are they?
What is the typical flow rate when clean?
How long before you need to clean them out?
Is it easy to clean them and does field cleaning restore the original flow rate?
What is your technique for using these bags?
Is there some gotcha that isn't obvious to me?
My thinking is that the simplest way to use one of these bags is to simply scoop up some water, then let the water drain into my pot, then pour the water from the pot into the water bottle.Feb 22, 2007 at 7:22 am #1379619
Jason SmithBPL Member
How much do the bags weigh?
Don't have a scale right now, will weigh it on monday at work but I would say around an ounce
How durable are they?
They are durable at the 20 micron size, don't know about smaller.
What is the typical flow rate when clean?
Pretty good for the 20 micron, again smaller micron might be slower but I think that It would still be acceptable in smaller sizes.
How long before you need to clean them out?
Unless you are useing really dirty water you really dont need to clean them. The smaller micron sizes might be different
Is it easy to clean them and does field cleaning restore the original flow rate?
Yes, Think of them like a mesh, they can be cleaned very easily by reversing the bag and wipping them a couple times to fling of any large particle of dirt then pour some of the clean water trough them in reverse.
What is your technique for using these bags? I place the bag over the mouth of my Wide mouth MSR Bladder I make sure a little of the bag dips into the bladder to form a small cup. Then using my pot I pour water into it.
Is there some gotcha that isn't obvious to me? Not really with the bigger sizes, again I was worried about flow and durability so started by purchasing a larger micron size. Now that I am happy with the current size, I am thinking of trying a smaller micron size myself. If you puchase a 5 or 10 tell me how it works.Feb 22, 2007 at 8:47 am #1379630
Laurie Ann MarchMember
@laurie_annLocale: Ontario, Canada
my filter is on the heavy side but I insist on taking it (Katadyn Pocket)
what I do is take a nylon collapsible water carrier and filter from that – there is less debris that way – the watercarrier weighs practically nothing and I find it helps.Feb 22, 2007 at 9:22 am #1379639
Jason, thanks for the feedback. The more I thought about the idea I had, of filling the bag filter then squeezing into a pot, then pouring the pot into a bottle, the more I realized this would be very unpleasant in near-freezing weather due to all the water on my hands and I'd probably lose patience with this system very quickly.
So I'm going back to the solution I used several years ago and which I'd forgotten about. Namely, use a McNett Aquamira water bottle with 2 micron cyst filter to collect water, then squeeze from this bottle into my normal 1.5 liter bottles, and possibly add Micropur tablets if I'm worried about bacteria or viruses. This system worked quite nicely, except I almost never used it because I was confident of the water most of the time, and I ended up chucking the thing after a few months on the road. As I recall, the bottle plus two spare filter cartridge (each nominally good for 100+ liters) weighed in at about 7 oz, which isn't bad for a filter.
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