I'm in the market for a portable water filter. What's the best value for the dollar in backpack style water filters?  Any links for online purchase would be appreciated.  Thanks.

MSR MiniWorks. Small, light, efficient, servicable. It also screws right onto MSR dromedary bags and big mouth Nalgene bottles

From their Website:
"Selected by the Amphibious Raids & Reconnaissance Division of the US Marine Corp as the filter of choice for Fast & Light missions"

[img]http://www.msrcorp.com/filters/images/miniworks.jpg[/img]
screws onto these:
[img]http://www.msrcorp.com/hydration/images/dromedary_bags_thumb.jpg[/img]
[img]http://www.msrcorp.com/hydration/images/hydromedary.jpg[/img]

or these:
[img]http://a1072.g.akamai.net/f/1072/2062/1h/gallery.rei.com/regularimages/664604.jpg[/img]



buy it here:
[url]http://www.msrcorp.com/filters/miniworks.asp[/url]
or here:
[url]www.rei.com[/url]

I like Pur for the money, but  Katadyn is the best for high volume, but they are quite expensive.

Be sure to consider the difference between a  "filter" and a "purifier". A purifier is a filter with the addition of a chemical "usually iodine" treatment stage. Also look at the difference between ceramic and cartridge filters.

Here is a link to a great place to buy all your camping needs.
[url]www.campmor.com/webapp/commerce/command/CategoryDisplay?cgrfnbr=253&cgmenbr=226[/url]

If I bought a filter and not a purifier, could I treat the water first w/ iodine and then filter it to remove the iodine taste?  Would this eliminate viruses?  Just wondering b/c filters seem much cheaper than purifiers and there seems to be some doubt on the effectivness of purifiers anyway.  Thanks guys.

You need to evaluate how many people you'll be filtering water for, where and what you'll be filtering, and who will be doing the filtering.

This is one of those items that either works great or agravates the hell out of you every time you use it.  I backpack all the time for days at a time.  You should also realize that many of the so called "purifiers" are simply filters that have iodine or chlorine tabs included in the box.  You can buy a filter like any mentioned here and some iodine tabs and you'd have a "purifier".  Basically the only time you will need to use the iodine on top of the filter is if you suspect that your water supply is contaminated with some sort of virus.  Otherwise most filters screen down to 0.2 or 0.3 microns which is more than small enough to filter out anything you need to worry about.

My preference is the Pur Guide.  It is very easy to pump.  It has a very high pump/volume ratio.  The major selling point to me is that there are no hinges to break.  I've read in several reviews that the Sweetwater and MSR models with the lever arms tend to break in colder (near freezing) or really hot weather.  Both environments require extra water consumption.  If you break the handle or a hinge on the MSR above, your screwed.

Join REI if you've got one in town.  I got over $1000 back in my yearly dividend this year.  It pays off in the end.

The MiniWorks I mentioned above has a carbon core in the filter to remove iodie and other chemical and make the water taste clean.

Our posts overlapped.  

If you do this you will need to filter the water first, then treat with iodine or chlorine (the chlorine drops are just chlorine bleach).  You need to get all the particles out that any virus could attach itself to before you treat the water.  But again if you suspect or know that the water is virally contaminated, you will ruin your filter core and have to treat the water every time you use the filter until you have a chance to decontaminate it.  Backflushing isn't good enough.  You need to strip it down and soak everything in a bleach solution (pump some solution through the filter first) for a couple of hours.  

What Muad_Dib said is on the money. Talk to the guys at REI, they are very helpful.




Yes, but you should prefilter the water, then add the iodine this would eliminate the virus threat. Refilter and then most of the chemical would be removed if the filter you choose has a carbon core. Just remember that you will get an accumulation of purifying chemical in your carbon.


Also consider that a cartridge filter you must replace the filter element (cartridge) more frequently, the elements are bulky, and last between 100 gallons and 1000 gallons before replacement is required. In SHTF situation this may not be the most desirable option.

Good ceramic filters last for over 10000 gallons before needing replacing but require frequent field cleaning. They are also prone to cracking due to being frozen.

I like the Katadyn.  I got it at a really good price (new), so I may be biased.  I filtered a gallon of water straight from the colorado river, put it in the fridge and had some the next day.  It was perfectly clear.  I've never seen water that clear before.  It looked like everclear.  No bubbles, nothing.  It tasted good too.  I'm one of those people who can taste iodine and chlorine in water and don't like the flavor.  

I have been using the PUR Hiker for the past 3 yrs. I have had no problems. Best bang for your buck IMHO.

Correct me if I'm wrong, but you don't have to worry about viruses in water except in the tropics.  I know the Katadyn ceramic filter will filter all bacteria.  The only question is chemicals.  I have the Combi with the activated charcoal filter which will remove a 90%+ of most chemicals, such as fertilizers, etc.  

It seemed when I was looking for info on filters and purifiers, most of the information available was pretty vague.  I would have preferred more specifics, especially an exception list of chemicals, etc. that the filters could not handle.

I'm not an expert at water filters/purifiers by no means, so please feel free to correct me if I blow it. Some believe that the filter/iodine combo purifier does not deactivate viruses because the contact time is not long enough and is relative to temperture. If the water is cold, more contact time is needed.

There are also two ratings for the pore size nominal and absolute. Remember, back in the biology 101, some bacteria shapes are not fixed, but something like a mass of jelly. So some could conceiably squeeze by a .5 nominal micro filter.

At REI, they have this iodine stuff, weighs about 2 ounces(I think it costs something like $10) that has an indefinite shelf life, but the disadvantage is that you have give the chemical time to do the job depending on time/temperture. The bottle has a simple thermometer. Its good against both bacteria and viruses, but I'm not too sure about giardia bugs. But you can't drink it right away, whereas filtered water you can drink. If wieght is a concern, this could be the ticket. I heard some where to keep you pack about 1/3 your body weight.

According to the REI guy, if you are mainly camping the U.S., you really don't need the virus part according to him, but in other parts of the world, i.e. Africa it will be different. But if you are in disaster mode where the local water treatment system is wiped out, what about sewage water that has overflowed into the local river or seeped into the water supply?

I agree with rnader to pre-filter larger particles to save your main filter. I use a Sweetwater pre-filter that works with most any pump-type filter, and is available at camping stores, but there is a better one out there that you have to buy thru the internet/mail but I don't remember where at the moment.

Like making fire, have several backups, in case one fails.

Try these links:
[url]www.rei.com[/url]
[url]www.campmor.com[/url]

Just found this piece in L.A. Times:
[url]http://www.latimes.com/news/local/la-000032601may08.story?coll=la%2Dheadlines%2Dcalifornia[/url]
A leading expert on chemical and biological warfare warned Tuesday that local officials must do far more to prepare hospitals and fire and police departments for terrorist attacks that could occur with little notice.

I have used the tablets, the PUR, and the MSRs. My vote is with the MSR Waterworks. In Alaska I have seen many Pur filter leak and break.

The only downside to the MSR is you'll want to get at least one of their water bags for filling. The bag is great but in some circumstances you'll want to fill something else and in some situations it can become difficult. (Though I have never heard of one breaking from normal use)

A little background first.  I thru-hiked the Appalachina Trail in 1995 (georgia to maine 2160 miles not including off trail miles into towns for resupply and r&r).  I spent approximately 6 months on the trail living out of my backpack.  Water filter use was a several times daily affair.

I saw and used darned near every water filter that was out there not just on the trail, but in my hiking experience before and since.

my observations.opinions.

The Katadyn filters are the best engineered water filters going.  With normal care and maintenance they should last pretty much forever.  However, the old style Katadyn Pocket Filter weighed a TON and was difficult to use.  It pumped slowly, requiring great pressure and you felt like you needed three hands or a VERY stable working environment to get efficient results.

The Katadyn minifilter is well made but too slow for practical use.

No Katadyn product is a purifier, but their excellence as microfilters is prety much unmatched. Katadyn makes excellent drip filters for basecamp and disaster management use.  A buddy has one and loves it.

MSR products are exceptionally field maintainable and their ceramic filter elements last darned near forever.  The plastic hinge is a potential weak point in extreme cold or heat, but, you ain't gonna use a filter in extreme cold (they freeze up solid in about no time flat) and in extreme heat you just need to pump a little slower to reduce the strain on the hinge.   The one CON I have on the MSR units is that they all pump slowly.   FOr group use or use in compromised water areas, the full sized waterworks is the better option over the miniworks.  For solo hiking, hunting, etc. in the US, the miniworks is a good choice.

First Need filters are trouble prone.  WHile technically in laboratory conditions, the First Need turns in excellent filtration performance (bordering on purification)  in the field they clog FAST and are difficult to clean. Repair is often impossible. I HATE THEM.

The PUR fil;ters are well designed and reasonably light weight, they pump faster than ANY other filters in thier respective classes.

The old style Explorer was the group champ.  THat thing could pump out a liter of water in darned near 30 seconds.  Routine cleaning was super simple.  It is bulkier and heavier than I like though and the iodine aftertaste, while mild, can take some getting used to.  I don't know if there is a non-iodine filter element on the market for this unit at this time.  The iodine matrix filter design showed some shortcomings in that the carbon post filters would strip out the iodine before it had a chance to kill viruses.  While the filter was still plenty effective, PUR withdrew the element from the market to avoid liability problems should someone use the element in a virus infected water source and become sick.   I still use the iodine filters units in my Explorer and Scout filter/purifiers.


Continued

The Scout is the iodine version of the current Guide model.  It's a great filter.  Slightly bulkier than some, but it has a great pump rate in either version.  I have a bottle adaptor (screws onto nalgene bottles and dromedary bags just like the MSR's . This gives me only 1 hose to manage and that's important (more on that later.)  The Scout is my primary filter.

The Hiker model from PUR is a beautifully compact, clog resistant microfilter that introduced PUR's current filter core design.  THe thing pumps pretty fast and is very small and light.  It uses two hoses and there are no screw on bottle adaptors for it.  Pur offers a stop top system that fits most bottle types.  One interesting feature for the Hiker is the ability to set it up on a syphon mode.  You hang your source water bag high, hang the Hiker filter slightly below that and run the hose to the clean water container below.  pump once or twice to get the water flowing and then allow gravity to do the rest.  It's slower than pumping, but it still works and allows you to do other things.


The Sweetwater Guardian is a POS in my experience.  I used one for approximately 1000 miles.  I used their inline prefilter, I doubled the foam pre-filter media in their intake filter and eventually wrapped the intake with a coffee filter for additional pre-filtering.  I still spent a lot of time cleaning clogs and replaced my filter elements WAAAY too often.  Eventually the pressure relief valve got clogged open creating a dangerous condition.   Contrary to company literature the water released by the pressure relief valve is dirty water. It can't be anything but since the only place pressure can build up in the filter is IN FRONT of the filter membranes, and that water is dirty. The only way to relieve that pressure is by venting water from the pressure vessel.  Venting dirty water which sprays all over everything.  The cleaning process on the sweetwater is also a dirty process strongly increasing chances of cross contamination.   While I still own a Sweetwater for last ditch use, I hate the thing.

Most of the really cheap filters work under restricted conditions, but I wouldn't trust them for long term use thanks to cheap construction or low production of water.

Continued

General filtering tips:

All filters will work better if you take a few elementary steps.

1. gather water from the clearest source possible.  If you must filter from a murky water source, gather water first in a container and allow the silt to settle out before filtering from the surface of the water.

2. Add a paper coffee filter over the intake of the filter hose.  This disposable filter will take most particles larger than around 10 microns out before it hits the filter membranes. It is these big particles that clog filters the fastest.  This WILL slow pumping a bit, but it is worth it in terms of filter life and time between cleanings.

3. Avoid cross contamination between intake and output. This is probably responsible for the VAST majority of so-called filter failures. NEVER let the intake hose touch the output hose. I always disassemble the intake hose from the filter prior to packing it away.  I drain the hose as well as possible and store it in a ziplock bag. I also cap the intake hose nipple with the cap the company provided to prevent contaminated water from exiting and contaminating the filter body and output hose.  I also pump out as much water from the filter as I can and drain the output hose as well as possible before putting it and the filter body in a seperate freezer ziplock. I also soak the entire unit in bleach solution following each trip, pumping water through the filter and hoses to ensure total coverage.  I store the filter dissassembled to allow it to dry fully between trips.

Filter performance is also influenced by user care.  If you keep trying to pump a filter that has become clogged, your chances of breaking the thing are pretty high, so follow directions and don’t be lazy. There was a run of PUR filter failures (mostly in the Scout line) in 1995.  I talked to many of the people who had failures and discovered that most of them ran the filters hard, never cleaning them and pumping them until they simply clogged solid before stopping to clean them.  That’s abusive treatment that resulted in crud being pressure packed into the filter matrix.  That ensured rapid clogging even after good cleaning. Repeating this treatment for a month (pumping to total clogging, resulted in excessive material fatigue in the threads where the endcap sealed the filter unit, leading to catastrophic, destructive failure.  User Error.

Disclaimer:  7 years have passed since my most intensive field testing. Sweetwater may have improved their abysmal design.  Katadyn has dramatically improved their Pocketfilter design, but it is still big and heavy.

Filter choice is largely dependent upon your use.  A hiking filter is not ideal for long term disaster management use, while a filter that is suitable for survival basecamp and disaster management use is generally too large and heavy for backpacking and tactical use.

Hope this helps.

Chemical purification:

Iodine:  As a sole method of purification iodine takes a while, a minimum of 20 minutes in room temperature water, in cold water total deactivation of microbes can take 8-24 hours depending upon how badly the water is contaminated.  It tastes like crap and it can be potentially hazardous for people suffering from thyroid and liver problems. A certain bacteria: cryptosporidia, is rather resistant to iodine disinfection.

Of commercial iodine treatments, PolarPure (a liquid solution that is renewed by adding water to the jar which contains crystaline iodine) is easy to use, lasts a LOONG time and the iodine flavor is bearable.

Potable Aqua is a tablet form.  In terms of gallon to gallon disinfection, it it much more expensive than Polar Pure.  It also tastes pretty bad.  I used it a lot on my thru-hike when I was trying to make major miles during a day and didn't want to spend time unpacking, filtering and re-packing gear.  I keep it in my cars for emergencies.  I now use Polar Pure for solo backpacking when I need to keep pack weight to an absolute minimum.  (I can put up with iodine flavor and my body can take it.)

Chlorine:  It's even less effective than iodine.  It won't touch cryptosporidia in backpacker safe concentrations and practical contact times. In room temperature water, even overnight treatmnent is not 100% effective against many bacteria and viruses.  As a survival treatment at a basecamp where you can treat large amounts of water for longer periods of time, it is reasonably effective.

The new chemical system on the block is Aqua Mira.  It's effective and easy to use, but it's not cheap. I haven't used it yet.

Iodine bonds readily to vitamin C, so adding ground vitamin c to iodine treated water (after it’s had time to work) will bond the iodine to the vitamin c and takes the taste away. It also allows the iodine to be quickly precipitated out of your body.

I've got a a OLDIE,
First Need water filter, this was before they had the widemouth nal. adapter built onto it. i had to buy it extra $5 so it was easy to do. worked good while i did backpacking. the first need filter was not a very well built unit (it was solid but its pump mechanisim could have used some work. when you pulled the t-handle up the inlet tube (rubber, thick surgical hose) would flatten so it wouldnt pull alot of water.
so i would not recommend it. if i were to go backpacking i would still use it. providing it still filtered dye from water. while the dyetest is not a tell-all successful test it does let you know if its working well.

de nada, it's another one of my obsessions.

at least its a safe obesssion, even the antis have to admit to that one.

Thanks from me too. I own one of those Sweatwater Purifiers with the iodine attachment that I bought it on sale at REI Co-op for $30. Sweetwater has been bought out by another company, and they have discontinued selling the iodine attachment claiming that they can not verify that it meets the FDA's definition of purifier. But I will still used keeping in mind the limitations that you mentioned.

Thanks for all the good info. !

I've got the PUR Scout. Love it. Easy to use.

my vote is for either the PUR hiker or scout...pumps fast... and mine has held up in the desert and mountains here in AZ...very tough filters

Thanks for all the replies.  You guys know your filters and I now feel like an educated shopper!  I'll either be going with a PUR Guide or the MSR Miniworks.  Any final suggetions on these two models?