Water filter comparisons

[Dale Wambaugh]

I’m considering a new water filter and have some to compare.

MSR Sweetwater Guardian (found a possible deal) I do like the idea of a cleanable filter and being able to treat for virii at my descretion.

Katadyn Hiker Pro ($50 at Campmor). Looks like a nice balance of price, weight, and filtering capacity.

Katadyn Exstream– looks compact and easy although capacity is low and it’s only a couple ounces lighter than some of the pump-style filters. My question on this one is can you drink from this without turning your face inside out trying to suck water through the filter? I tried another bottle style filter and I wasn’t impressed.

Or your favorite?

I use Aqua Mira but I’d like to be able to grab water on the way and not mixing and waiting. I have an old First Need that is an anchor and big on pack volume too.

[Anonymous]

Dale,

A nice technique taught to me by an adventure racer friend for aqua mira is to premix it into a separate dropper bottle a little before you stop. When you get your water fill up with all you can carry (I carry two 1 liter platy’s) and drop in the aqua mira. Keep walking until the water is safe to drink, then down one of the liters and use the rest to carry you on to the next water source. It works nicely at the weight expense of a tiny dropper bottle and its even faster than a filter.

I have used the Hiker Pro and it works well enough although I think for filters making your own gravity filter is THE way to go. Its both lighter and easier to use. I made one according to Ray Jadine’s design that weighed just a hair over 6 oz. Just dip it in, hang it and wait 2-3 mins for two liters. If you will be doing other things and use a platy the “filter link” adapter makes it so you don’t even have to montior the filling.

-Friendly anonymous poster-

[Mike Storesund]

I have the Katadyn Hiker Pro and the MSR Waterworks, of the two I prefer the Katadyn for ease of use and cleaning. However, I do like how MSR will accept a wide mouth Nalgene product directly.

The anonymous poster mentioned a gravity filter, and that truly is my preference now, in addition to Aqua Mira. I have made a couple by using Platypus reservoirs and an in-line filter. I would not recommend using your bladder hose as the length of hose for your filter though. I have not been into making too much of my own gear so the H2O Amigo by Ultralight Adventure Equipment is what I use. Either way (Platypus reservoir or H2O Amigo) you are looking at about $45 +- for a gravity filter. It’s nice to just hang the water and let it fill up your water bladders while you set up camp or get your kitchen ready. I still use Aqua Mira after filtering as an added precaution.

[Dale Wambaugh]

I have considered gravity filters and I came across some Platypus Big Zip bags that have openings at opposite ends to aid something like a Seychelle Eliminator filter mounted between. I am hiking in country with lots of streams and likes so the issues of dipping out of shallow springs and such isn’t an issue for me. I could fill a Platypus zipper in a heartbeat– in fact I’d need to hang on tight so it wouldn’t get lost in the current) I have plenty of resevoirs, so one Big Zip, some tubing, filters and two of the Playtpus adapters would do the trick. And yeah, I wouldn’t use my drinking tube as part of the filtering assembly– keep it clean and uncontaminated. Continual removing of the bite valve would make it leak too– I’d put money on that.

I would add some sort of silt filter ahead of the Seychelle to get the big chunks. I like the mechanical simplicty and I guess I could learn to miss the pumping.

Thanks for the input too!

[Mike Storesund]

Dale – That is the exact setup I made earlier. The Big Zip does need a little persuasion in closing its zipper without leaking. I put a Silt Stopper 5 micron pre-filter before the Seychelle Eliminator (2 micron) filter. I found that the filter needs to be at the far end (3 feet or so) from the source in order for it to work properly. Otherwise you would be waiting a longer time. When I placed it within 3 inches of the top reservoir it took almost 45 minutes to filter a 4 liter bag. Placing it almost 3 feet from the top bag it only took 4 minutes to filter the same amount. It must be the force of gravity through that tube that helps push it through the filter.
Having a shut-off valve in line would be nice too.

[paul johnson]

Dale, go for the MSR Sweetwater Guardian. Easy to pump. Handle, IME, is NOT easy to break – mine never did. Make sure that you pump the handle straight up and down. I personally believe that the handle breaking is a result of not doing so, but rather applying a lateral load to the handle while pumping. I find it easy NOT to apply such a load – hence, no broken handle. Also, it’s NOT ceramic, so you can use it in the winter. It pumps on both the up and down strokes.

Hiker Pro is nice, but my preference is the Sweetwater Guardian. The lever pumping action is easier, IMHO, than the linear pumping motion of the Hiker Pro. Also, i believe some of the newer Hiker Pros (’05??? ’06??? models) use a ceramic cartridge, so winter use is NOT advised as any water remaining in the filter can freeze and crack the ceramic filter element. Sweetwater Guardian doesn’t have this problem since it’s not ceramic (at least not my older model; not sure about the ’06 models, so you should check that).

The Exstream. Have it as well as the larger XR version which i have since given to my daughter. 1st third is easy to either squeeze or suck out. 2nd third requires some sucking and/or hard squeezing. Final third of the volume is great for developing grip/forearm strength as well as rekindling memories of that old suckling reflex. Bored? Restless? Need something to do after making camp? A few minutes squeezing and sucking on an Exstream filled only 1/3 full will do wonders. Exstream is expensive as even on sale the replacement ViruStat cartridges can be a bit expensive, plus, IIRC, they’re only good for 100L vs. 200L for some other Pump Filters.

Also, as for the virus issue, AqM or UV-C is the way to go. I steer clear of the anti-viral drops due to the taste, though there is another chemical that can be used to help alleviate the chlorine taste after using the “drops”.

Hope this info helps.

[Rob Zwissler]

The “SweetWater Purifier Solution” or “Viral Stop” that comes with the Sweetwater filter is 3.5% Sodium Hypochlorite, aka household bleach. No reason you can’t use bleach with the Hiker (Pro) for the same effect. If you look at reviews on outdoorreview.com, the Sweetwater has an averate of 3.52/5 with 105 reviews (http://outdoorreview.com/cat/outdoor-equipment/backpacking-camping-hiking/water-filters/SweetWater/PRD_77105_2960crx.aspx) while the Katadyn Hiker has a much better 4.47/5 with 117 reviews (http://outdoorreview.com/cat/outdoor-equipment/backpacking-camping-hiking/water-filters/SweetWater/PRD_77105_2960crx.aspx), looks like a lot of complaints with the SweetWater have to do with clogged filter, handle breaking. I have no idea how many of these are issues which have since been resolved, but it’s worth some research.

Have you considered the Katadyn Mini filter – like the Hiker but smaller and lighter, or the MSR MIOX?

Rob

[Matthew L.]

I agree with Paul on the Sweetwater Guardian. It has been a very reliable and effective filter for me all year long. While I usually only use AM now, it is nice to know that I have it when I go somewhere with very questionable water. It is quite durable as long as one uses it intelligently.

[Douglas Frick]

>I am hiking in country with lots of streams

PJ mentioned UV-C. I’ll also make that recommendation, since your water is already pretty clear to begin with. I use the AquaStar Plus (3.8 oz not including bottle) which kills pretty much everything, including viruses. It’s very nice to dip a bottle of water and drink it one minute later, without changing the taste of the water. Almost as good as the filter-free days of yore. The only time I had a problem was with water fresh out of a snowfield: it was too cold for the Aquastar (original, not Plus) to reliably treat so I had to wait for it to warm up a bit.

[paul johnson]

Douglas, I’m becoming a bigger and bigger fan of UV-C. I like the AquaStarPlus also. I would like to expand a little on your comments, both pluses and minuses, on the use of UV-C in general and ASP (AquaStarPlus) in particular.

First, a plus for ASP: the newer Plus unit looks pretty much the same as the original, but is made of different materials. I had a telcon some months ago with an engineer at AquaStar. He told me that the ASP unit looks fragile, but really no longer needs the included 1Liter Lexan bottle to protect it. He challenged me to perform a test that he had performed many times. Throw the “naked” ASP unit (w/o the Lexan bottle protecting it) as hard as i could onto a tile floor. He said it would just bounce around and NOT break. “Naked”, w/o the Lexan bottle, the ASP is lighter than the SteriPen (my first UV-C purifier – also a very nice device). The ASP light generating unit is made of a different material than the orginal AquaStar unit.

On the downside, particularly for some geographic areas, UV-C (and chems, for that matter) won’t kill larger parasites (i.e. Hydatid tape worms). It would take ~28x the intensity of UV-C light produced by ASP or SteriPen to produce a 98% reduction in viable tape eggs.

Hydatid tapes are endemic to certain geographic areas, though theorectically they could be found in water sources anywhere wild or feral canines are found. The good news is the eggs are about 25microns in size. So, a good silt- / pre- filter should eliminate them before chemical or UV-C treatment is performed.

Here’s a link to an earlier post on this subject some info on Hydatid tapes. Also, anyone can search these Forums using the “Search Forums” (NOT the “Search BPL”) LINK (NOT the “edit box”/”text field”). The link has a default color of blue unless one has changed their Browser’s color scheme.

Lately, after a few years of AquaMira use, i’ve been moving over to either a pump filter (or gravity filter, a ULA Water Amigo, and a UV-C purifier combination (fitler first, then UV-C). From my personal perspective, better safe than sorry.

I’m also planning, this year or next, to try the First Needs water pump-filter. It has an anti-viral stage like the ExStream. Also, a CamelBak in-line filter when i use a bladder. I’ll have to read the box and insert for the CamelBak in-line filter though to see if it has an anti-viral stage. Otherwise, i’ll use UV-C first (after prefiltering the water).

[Michael Wands]

Just got my Katadyn Mini in the mail yesterday from REI – used a 20% coupon.

Only 8oz, easy to maintain, has 2000 gallon capacity. Only pumps .5 liters per minute, but I used to wait 5 minutes before using Aqua Mira drops and then another 30 minutes to drink.

Will take it out this weekend, but I went around the neighborhood last night and filtered everything in sight!!! Bird baths, fountains, standing water by curb. Seems to work pretty well.

I still prefer MP1 for fairly pristine water sources at elevation, but in the flatlands of Texas where agricultural and industrial run-off are often a problem, I think the Katadyn Mini might be an ideal solution.

By the way, I have a Steri-Pen that worked only 2 days before the platic arms holding the batteries in place broke apart. I also have a Sweetwater Guardian microfilter that I have used for years – never gotten a bad drink – but it just seems like overkill for one hiker.

I have an outback filter bottle and a safewater anywhere filter bottle, but at 2 microns of filtration, I just don’t feel really comfortable.

[Dale Wambaugh]

Michael, I did read a couple owner reviews where some heavy-handed folk broke their Katadyn Mini the first time out. As with the Sweetwater Guardian, it make just take a little more brains than brawn. As with any UL gear, hitting it harder won’t make it work better. If I remember right, the Hammer Method of repair was brought about by Ford products and exported overseas with Lucas electrical parts :)

I’d read several reviews where people had a hard time getting their pumps to draw water. I’ve had good luch putting my thumb over the intake (and in the water) and pumping a few strokes to build up a little suction and compress some of the air in the system. Getting the filter going in the sink at home before heading to the trialhead might solve some of this too– the pump gets so dry it can’t create enough suction and/or gets an air lock. Many pumps for wells need a little water to prime them too.

[Dale Wambaugh]

I surfed on the CamelBak in-line MicroFilter and came up with a bunch of police and “tactical” supply houses seeing it for $60-$70. It looks interesting and it filters down to 0.2 microns. CamelBak has a tablet to add to your water to kill more bugs along with the filter.

Any good sources for the filter? Other than the (gulp) price, it looks good for a home-brew gravity system.

[paul johnson]

$52

[Anonymous]

anyone know how the camelbak in line compares to the seyschelle?

[paul johnson]

Seychelle is merely a cyst filter. It’s pore size is 10x larger than the Camelbak. If bacteria are an issue, then the Seychelle ***ALONE*** won’t suffice. Please see Ken Helwig’s later post below (or above is displaying this Thread in Rev. Chrono. order) for the solution (no pun intended) to this issue.

[Bruce .]

I used a sweetwater for years with no issues whatsoever, but just changed to a gravity filter just to try one out. It’s lighter, and I kinda like the idea of filling it up & letting it do it’s thing while setting up camp or whatever.

[Ken Helwig]

But adding some AM to the mix will kill all the goodies.

[Einstein X]

I made my own inline set up for last years Scotland trip. It consisted of an one liter platy than the drinking tube than a filter pen (not sold in the US) a valve and than the mouth piece. So i added unfiltered water to my platy and just filtered by sucking water. At home it worked well and you don’t have to turn your face inside out to get some water. Unfortunately the filter got clogged on the first day, filtering clear water.

The positive effect of that was that from than on i had to drink water straight from the burn. Now i know it is like playing dice cause the deer also come to the highest places in Scotland but luckily i did not get sick. And what i really liked was comming to a stream, dipping my pot in the water and gulping down 0,85 liters without having to wait, thus drinking more and being beter hydrated.

I would also like to give my 2ct’s on chemical water treatment:

I am very sceptic about the ability of a chemical to do anything about viruses.

A virus is a piece of genetic code, DNA, it is not alive so you cannot kill it! Experiments have been carried out with viruses being placed on the tip of a bullet, than being shot into a piece of concrete. This unleashed G-forces of at least hundreds, maybe thousands to the viruses and they survived! Now i don’t feel comfortable in adding a chemical to my water to kill something which isn’t even alive. I contacted a company selling an AquaMira-like product. They explained that a virus needs a host, i.e. a bacteria, to work. Without a host the virus will become inactive, but can become active again! So kill the bacteria you also eliminate the virus.

Now the representative of MIOX told me that some viruses (about 4%) can be found without a host body. These viruses cling together, called a macrovirus. He told me that the MIxed OXidants of MIOX did get rid of these macroviruses though he couldn’t explain how or why. He did say that MIOX is even effective against anthrax! But than you have to wait for at least 8 (!) hours befor drinking, which is kinda hard when thirsty.

So the fact of the matter is i’m very sceptic about the effects of chemical water treatment agents on viruses. Not to mention what i does to the human body.

To relevate what i said above:
1. filtering or purifying is always beter than playing dice like i did in Scotland
2. be sensible, if you suspect anthrax is in the water than don’t drink it (duh)

Eins

[Anonymous]

Viruses are still organic and there is more to them than just DNA or RNA. Nucleic acids, envelopes, capsids, enzymes, are all still vulnerable to the laws of chemistry. If you use highly reactive substances you can disrupt viruses just like anything else. A naked piece of genetic material is generally not infective. You have to have all the virus pieces for it to be infective.

[paul johnson]

First, many chems do generally make quick work of viruses. A quick swipe of an alcohol pad and a site is prepped for injection or IV. Chems are used to prepare a site for surgical incision. Walls, floors, and other surfaces are wiped with chlorine or other disinfectants. Must be something to it. Were it not so, why would hospitals use them as a disinfectant? Ethylene gas (a chemical) [or steam autoclaving] is often used to sterilize rolls containing surgical instruments or gauze and bandages.

There is so much evidence that chems erradicate viruses that it is ludicrous to think otherwise. Some viruses are a bit more resistant but still can be inactivated by chems.

A virus particle basically consists of either a RNA or DNA (not both) central core surrounded by a protein sheath. It is correct that viruses (or virii if you prefer – both are correct) are not living organsims (they don’t respire, they don’t metabolize, they don’t respond to stimuli, and they can’t reproduce without the aid of a host).

However, this does not mean that they cannot be inactivated. Their encapsulating protein structure is easily denatured, making them incapable of attaching to the virus receptor sites on potential host cells. Think of it sort of like two pieces of a Jig-saw puzzle. The two pieces must “fit” together in order for a virus to infect a host cell (though in the case of a virus and a human cell, the “jig-saw” aspect is really more related to “charges”, i.e. pluses and minuses, of the proteins – not so much that they are ions, but all chemicals have these physical properties associated with them. Some areas are more positive than others, and some are more negative. These portions of the proteins and biochemicals/biostructure must “fit” together. Take this illustration “with a grain of salt” – it is NOT precise, but rather a simplification.

Other than nerve cells (which is why rabies can easily cause an infection in both animals and humans) the virus receptor sites generally differ greatly from plant-to-plant and animal-to-animal, sometimes even within a species (e.g. in some cases unrelated humans may not become infected by another’s virus – though there are other reasons for this also). These differences in virus receptor sites make viruses in many cases very specific for a particular organism. Mutation of the virus being required for infection of another species (e.g., currently in the news relative to this matter is the “bird flu” virus).

Chemical reactions with disinfections (and also heat – see below) changes the structure of the protein sheath, making infection by that affected virus particle unlikely or impossible due to the change to the protein’s structure. Chems can also affect the RNA/DNA core of a virus particle.

As far as the “bullet”. I’m very skeptical that such is possible. In fact, i simply don’t believe that it is possible. Why? The quaternary structure of protein generally denatures (basically unravels or “cooks”) at or below 140 deg F. The heat generated by firing a bullet, not to mention its impact and resultant rapid decceleration, which once again produces heat by converting kinetic energy to thermal energy due to friction, is much more than sufficient to “cook” the little buggers, but good. The G-forces AREN’T the issue; the temperature/heat IS the issue. Out of billions of viruses on a bullet could one make it through? I don’t know; i haven’t personally conducted an experiment of this nature. However, even if one could, one viral particle probably isn’t sufficient to cause an infection – a larger viral load is often required.

In fact, think about a thermally attenuated vaccine for a viral disease. Heat clearly can do the job to prevent a full blown infection from a vaccine. A bullet being fired and strking an object – both events produce heat.

I can readily understand one’s reluctance to accept certain things as true. I too fall into this error from time to time. For example, having been taught otherwise about Permethrins in an advanced “Entomological Pests” course over 30yrs ago, i was very reluctant to believe that it is safe to treat clothing with Permethrins in many (most???) cases – some people do have bad reactions if inhaled; this is well documented. However, the bottom line in this case was I WAS WRONG. “Buzz Off” clothing has been using Permethrins for some time now, and other experienced Posters to these Forums were patient enough to educate me about my error – for which I thank them. Goes to show, one is never too old to learn – even in my case. I only mention this to try to show that i can understand the other Poster’s reluctance to believe certain things.

As for Bacillus anthracis (a relatively large/long gram-positive rod shaped bacterium, not a virus), which is the etiological agent of the disease Anthrax, forms endospores which resist heat (5min boiling should kill them, but perhaps not 1-2minutes), desiccation, chems, and UV light to some extent.

I was unaware of an 8hr time limit for MIOX to inactivate B. anthracis (its endospores, no doubt; not the unprotected bacterial cells). I wonder what the half-life of the mixed oxidants are? That is, are they still effective after 8hrs? I don’t know. I would like to see other confirmation of this 8hr contact time.

Not all viruses are found inside of bacterial cells. These are particular types of viruses, often termed bacteriophages. Even E. coli has a particular bacteriophage which infects it – the T5 bacteriophage. IIRC, the “burst size”, that is the number of replicated virus particles that can fit inside of an E. coli bacterium before it ruptures or bursts is about 200. This give us an idea of how tiny viruses are and why they can’t be filtered by mechanical barrier filters. Some viruses are larger than the T5 bacteriophage, however, but still much smaller than bacteria. The “burst size” concept is also mentioned since this is part of the infection process and infection/disease progession inside of a human also.

Some viruses are found in nasal secretions, mucus, saliva, and droplet nuclei (those tiny drops that spray out of our partially closed mouth and lips at ~200mph when we forcefully sneeze and spread our “germs” – some are too small to be seen by the naked eye and can be easily inhaled, thus spreading the infection). Viruses are also found independent of bacterial cells and also independent of human cells in our blood and lymph, and other body fluids as mentioned above.

Baceteria are not necessary for the spread of a viral illness. Touching contaminated inanimate objects, like door knobs, etc. and then transferring the viral particles to our mucus membranes, lips, eyes, nose, or into “broken” skin can produce infection. No need for a bacterial vector here. Maybe, i’m just forgetting, but i don’t know of a bacterial vector for a human viral illness. Arthropod vectors for human bacterial / rickettsial diseases, yes, but i can’t recall a bacterial vector for a human viral illness – maybe my “old-timers” is just acting up, but i don’t think that there is one.

Anyways, i hope this post helps to clear up some confusion.

[Vick Hines]

Killing viruses. Any organic material, including any virus, is oxidized by chemical treatments. They all work the same way and they all kill viruses… with or without hosts. Viruses are particularly vulnerable to oxidizing agents because their small size makes them more ‘available’ to the oxicizer. There is less matter to ‘burn through.’

[Einstein X]

>Anyways, i hope this post helps to clear up some confusion.

Yes it certainly did. Thanks for that Paul. Now why can’t the distributor of these chemical agents here in Holland give an awnser like this. If he could would have made me sell so much easier.

Thanx again Paul

Eins

[Katie Bolek]

Hi — I work for MIOX Corporation and just noticed the comment by Einstein X on 05/20/2006 07:22:00 MDT regarding 8 hours of required inactivation time for Bacillus anthracis (Anthrax). I’m not sure where that data came from, because the actual Anthrax studies performed by the U.S. government’s Dugway Proving Ground in Utah stated a 20-minute wait for 4 log inactivation (99.99%) of Anthrax, albeit at a dosage 4X more than the normal dosage delivered by the MSR MIOX Purifier. The spore stage of the Anthrax virus is much more resistant than regular viruses, so if there’s a chance for biological or chemical warfare activity in the region, the user may want to multiply the dosage. Note that regular viruses are inactivated with the standard dose within 15 minutes. Thanks!

Katie Bolek
MIOX Corporation

[Rick Dreher]

Hi Katie,

Thanks for your post, it’s always great to have a manufacturer’s representative participating on the boards!

If you’ll indulge a correction from a civilian, anthrax is a bacterium, not a virus. I don’t think this affects the inactivation stats you’ve provided.

Best,

Rick

http://www.bt.cdc.gov/agent/anthrax/faq/

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