Backcountry Forum
Backpacking & Hiking Gear

Backcountry Forum
Our long-time Sponsor - the leading source for ultralite/lightweight outdoor gear
 
 
 

Amazon.com
Backpacking Forums
---- Our Gear Store ----
The Lightweight Gear Store
 
 WINTER CAMPING 

Shelters
Bivy Bags
Sleeping Bags
Sleeping Pads
Snow Sports
Winter Kitchen

 SNOWSPORTS 

Snowshoes
Avalanche Gear
Skins
Hats, Gloves, & Gaiters
Accessories

 ULTRA-LIGHT 

Ultralight Backpacks
Ultralight Bivy Sacks
Ultralight Shelters
Ultralight Tarps
Ultralight Tents
Ultralight Raingear
Ultralight Stoves & Cookware
Ultralight Down Sleeping Bags
Ultralight Synthetic Sleep Bags
Ultralight Apparel


the Titanium Page
WM Extremelite Sleeping Bags

 CAMPING & HIKING 

Backpacks
Tents
Sleeping Bags
Hydration
Kitchen
Accessories

 CLIMBING 

Ropes & Cordage
Protection & Hardware
Carabiners & Quickdraws
Climbing Packs & Bags
Big Wall
Rescue & Industrial

 MEN'S APPAREL 

Jackets
Shirts
Baselayer
Headwear
Gloves
Accessories

 WOMEN'S APPAREL 

Jackets
Shirts
Baselayer
Headwear
Gloves
Accessories

 FOOTWEAR 

Men's Footwear
Women's Footwear

 CLEARANCE 

Backpacks
Mens Apparel
Womens Apparel
Climbing
Footwear
Accessories

 BRANDS 

Black Diamond
Granite Gear
La Sportiva
Osprey
Smartwool

 WAYS TO SHOP 

Sale
Clearance
Top Brands
All Brands

 Backpacking Equipment 

Shelters
BackPacks
Sleeping Bags
Water Treatment
Kitchen
Hydration
Climbing


 Backcountry Gear Clearance

Page 1 of 3 1 2 3 >
Topic Options
Rate This Topic
#89246 - 02/06/08 07:05 PM water filter cross-over
blazer209 Offline
member

Registered: 02/05/08
Posts: 31
Loc: California/central
Last few years I've switched over to ultra-light mentality.One bulky item that remains in my pack is my Katadin Filter.Thinking about switching over to a MSR Miox.Anyone have an opinion on this thing, or maybe an alternative?Appreciate any feedback.

Top
#89247 - 02/06/08 08:01 PM Re: water filter cross-over [Re: blazer209]
Ben2World Offline
member

Registered: 10/26/04
Posts: 1754
Loc: So Cal
Save your money.

Micropur tablets (one tablet per quart or liter) can do absolutely everything that MIOX can do -- and just as well and just as fast. No worries about circuitry failure or running out of salt or battery...

Top
#89248 - 02/06/08 09:54 PM Re: water filter cross-over [Re: blazer209]
Ecrow Offline
member

Registered: 02/02/08
Posts: 85
Loc: N. New Mexico
Ben is right, portable aqua also kills everything, leaves no taste, is small and light. Leave all of those pounds at home.

Ecrow
_________________________
Ecrow
Live to tell.

Top
#89249 - 02/06/08 10:19 PM water filter cross-over> The NEXT step [Re: blazer209]
300winmag Offline
member

Registered: 02/28/06
Posts: 1342
Loc: Nevada, USA
Well, I've gone from a PUR filter (now Katadyn) to Katadyn chlorine dioxide tablets and now I'm going to a SteriPen UV treatment W/ chlorine dioxide tabs as a back-up.

To me chlorine dioxide tabs are far too slow. UV treatment is much faster even with several bottles being used to fill a hydration bag.

Conversely, UV treatment can be used for one or two bottles for immediate use and Chlorine dioxide tabs for a hydration bladder to be used in an hour ot two after treatment. Either way I think we'll be carrying both methods of treatment if we're smart.

Eric
_________________________
"There are no comfortable backpacks. Some are just less uncomfortable than others."

Top
#89250 - 02/06/08 10:21 PM Re: water filter cross-over [Re: blazer209]
speyguy Offline
member

Registered: 04/11/06
Posts: 35
Loc: Portland, OR
If you're still into filters the new MSR HyperFlow looks good and weighs in at 7.4 oz. They are not quite out yet, but it's getting close. I'm thinking I may get one. However, I used Aqua Mira for the first time last year and liked the simplicity and the fact that there was no pumping.

Top
#89251 - 02/07/08 05:42 AM Re: water filter cross-over> The NEXT step [Re: 300winmag]
Pika Online   content
member

Registered: 12/08/05
Posts: 1814
Loc: Rural Southeast Arizona
I'll second 300WM's recommendation. I used a Steripen adventurer with Katadyn Micropur chlorine dioxide as backup for all of last year; probably a total of 30 days in the field. I had no problems with either circuitry, battery failure or GI distress. The Steripen weighs 3.6 oz with batteries and the batteries will last through at least 40 liters of water by my count. Extra batteries weigh about an ounce. The water you treat has to be pretty clear or the UV is much less effective; I use a coffee filter if necessary and if the water is really murky (not too uncommon in Arizona) then I go ahead and treat with the Micropur as a follow-up. The thing I like about the Steripen is that there is no swimming-pool-water taste when you use it.
_________________________
May I walk in beauty.

Top
#89252 - 02/07/08 08:25 AM Re: water filter cross-over [Re: speyguy]
BarryP Offline
member

Registered: 03/04/04
Posts: 1574
Loc: Eastern Idaho
Good find. 7.4oz and 3L/min are so neat <img src="/forums/images/graemlins/cool.gif" alt="" />!
However it won’t remove chemicals from the water (my fear <img src="/forums/images/graemlins/tongue.gif" alt="" />) like their claimed MiniWorks or SweetWater.
-Barry

Top
#89253 - 02/07/08 09:12 AM Re: water filter cross-over [Re: blazer209]
blazer209 Offline
member

Registered: 02/05/08
Posts: 31
Loc: California/central
Thanks for the great input.Yeh,my only reluctance has been due to time it takes for chemical methods to work.That's one reasons I've stuck with a simple filter for so long.You pump then drink.I'll definitly be trying these suggestions out.Thanks again.

Top
#89254 - 02/07/08 10:50 AM Re: water filter cross-over [Re: blazer209]
Earthling Offline
member

Registered: 02/22/03
Posts: 3228
Loc: USA
They are different systems all together.

If you just want water that's biologically clean then the tabs are ok.

If you are unsure, or know there are chemicals in the water source, then you want a filter IME.

Even the SteriPen,et al do not remove chemicals, so keep this in mind, depending upon where you tread on YOUR trips <img src="/forums/images/graemlins/smirk.gif" alt="" />

The weight trade is also a health trade IME.
_________________________
PEPPER SPRAY AIN'T BRAINS IN A CAN!

Top
#89255 - 02/07/08 03:44 PM Re: water filter cross-over - Siphon FIlter [Re: blazer209]
Brumfield Offline
member

Registered: 12/23/07
Posts: 255
Loc: Expat from New Orleans, now in...
Blazer, buy the Katadyn Siphon filter. It's a quality medical grade ceramic cartridge with a plastic tube. It will filter 5000 to 20,000 gallons using a 0.2 micron ceramic filter at 1.40 gallons per hour (3 oz per minute). Weighs 16 oz. You will be able to filter enough water for cooking, drinking, washing dishes, and clothes and even bathing if your raw water supply is questionable. I built one of these about 16 years ago and it still works perfect. This unit will offer you a back up water supply for your home too.

Be very wary of the units, such as the Katadyn Camp filter, that only use a charcoal and/or string filter. They cannot deliver safe water, just filtered water. Gravity filters last 30 times longer than a pump filter.

When you get in camp, start your filter and you'll have water ready before dinner is done... with NO pumping. I use a gallon zip lock bag as my raw water supply raised above my Nalgene, or above my 2 1/2 gallon collapsible UL plastic jug at the bottom to catch my water. You can clean the filter with a scrubby pad in about two minutes, and that is not needed often. No moving parts to break either! Brum

http://products.katadyn.com/brands-and-products/produkte/Endurance_Series_23/Katadyn_Siphon_26.html
_________________________



Top
#89256 - 02/07/08 09:48 PM Re: water filter cross-over - Siphon FIlter [Re: Brumfield]
blazer209 Offline
member

Registered: 02/05/08
Posts: 31
Loc: California/central
Thanks for the info.Since posting this I have had some change of thought.I never really had concern about anything but living organism type contamination.Wasn't really thinking about chemical type dangers.Thanks again for the input.My eyes are a bit more opened.

Top
#89257 - 02/08/08 07:26 AM Re: water filter cross-over - Weight versus safety [Re: Ecrow]
Brumfield Offline
member

Registered: 12/23/07
Posts: 255
Loc: Expat from New Orleans, now in...
Quote:
Ben is right, portable aqua also kills everything, leaves no taste, is small and light. Leave all of those pounds at home. Ecrow


Yes, Ben and Ecrow, Katadyn portable aqua tablets and all other chlorine based chemical treatments, or the Miox "new" (actually 100 year old) process of creating chlorine from salt electrolysis, can be used to kill some bacteria, some viruses, and many harmful pathogens. However, if no additional protection is provided against the bacteria that is attached to particles suspended in your raw water, then the limited efficiency of inactivation by chlorine will attribute to the continued presence of bacterial aggregates in all types of suspended particles. Particle-attached bacteria are universally more resistant to disinfection than are suspended bacteria.

To put it more simply, the particle-attached bacteria do not die as quickly, if at all, with chlorine treatment. You really should remove the particles and the micro size critters attached to the particles, not just kill some of them and then drink them down. They don't just simply dissipate into thin air when you chlorinate them, they are still there, and the now dead "bodies" of the bacteria and viruses are going into your system. <img src="/forums/images/graemlins/frown.gif" alt="" />

I use solar treatment when I can by placing my raw water in gallon zip lock bags in direct sunlight. Ultraviolet (UV) light destroys DNA and thereby prevents microbes from reproducing. That's all the SteraPen does, it adds UV rays to your water supply.

After UV treatment, ceramic filtering, and chlorine dioxide treatment of the water, I then carry 32 ounces of my water in a clear plastic bottle on top of my pack so it's exposed to the sun's UV rays most of the day. I always carry two 32 ounce bottles of ready-to-drink water. One in the pack and one on top receiving continued UV treatment, and rotate them out as I treat a new water supply.

Also remember that chlorine based treatment alone does not remove any harmful chemicals or heavy metals. To me, weight saving does not win out over safe drinking water. I cut down on weight where it won't harm me. EG: I changed out my leather belt with the metal buckle for a nylon webbing one with a plastic clip and saved 7 ounces. That alone is half the weight of my ceramic filter. Brum
_________________________



Top
#89258 - 02/08/08 09:37 AM Re: water filter cross-over - Weight versus safety [Re: Brumfield]
Ben2World Offline
member

Registered: 10/26/04
Posts: 1754
Loc: So Cal
Brumfield:

The above chlorine dioxide products all have concentration and treatment time that take into account the "clumping / particle-attachment" of baddies.

Top
#89259 - 02/08/08 04:51 PM Re: water filter cross-over - Weight versus safety [Re: Brumfield]
Xelif Offline
member

Registered: 07/04/07
Posts: 241
Loc: Bay Area, California, USA
Quote:

To put it more simply, the particle-attached bacteria do not die as quickly, if at all, with chlorine treatment. You really should remove the particles and the micro size critters attached to the particles, not just kill some of them and then drink them down. They don't just simply dissipate into thin air when you chlorinate them, they are still there, and the now dead "bodies" of the bacteria and viruses are going into your system. <img src="/forums/images/graemlins/frown.gif" alt="" />

After UV treatment, ceramic filtering, and chlorine dioxide treatment of the water, I then carry 32 ounces of my water in a clear plastic bottle on top of my pack so it's exposed to the sun's UV rays most of the day. I always carry two 32 ounce bottles of ready-to-drink water. One in the pack and one on top receiving continued UV treatment, and rotate them out as I treat a new water supply.


I think you'll find that almost all plastic blocks UV quite well - the SteriPen in fact depends on this in order to prevent burning you with UV light. So, the plastic bag in sunlight doesn't do anything other than warm the water and degrade the plastic a little bit faster.

Also, the SteriPen suffers from the same problems that chlorine does - bacteria attached to large particles can be shielded from light. It also has taken this into account as the chlorine dioxide products have, as long as the water isn't too cloudy.

Finally, the dead bacteria isn't going to hurt you. Viruses with disrupted genomes won't do much either. It is a bit creepy though. Just a bit of extra protein and carbohydrates though ;-) Bacteria that produces persistent toxins (such as botulism) aren't likely to be in our wild drinking sources.

I like my SteriPen and I use chlorine tablets as an alternative, just thought I might comment on this.
_________________________
- John

Top
#89260 - 02/08/08 06:51 PM Re: water filter cross-over-Plastic-UV-botulism [Re: Xelif]
Brumfield Offline
member

Registered: 12/23/07
Posts: 255
Loc: Expat from New Orleans, now in...
Xelif wrote:
"I think you'll find that almost all plastic blocks UV quite well - the SteriPen in fact depends on this in order to prevent burning you with UV light. So, the plastic bag in sunlight doesn't do anything other than warm the water and degrade the plastic a little bit faster."

Brumfield wrote:

Sorry, plastic does not block UV rays. However, plastic coated with Nanoscale titanium dioxide particles will block UV. My plastic drink bottles that I use on the trail to UV treat my water with are not coated with Nanoscale titanium dioxide particles. The SteraPen's plastic design is for strength and weight savings, not to block the UV rays. Unless, of course, the SteraPen's plastic handle area is coated with (everybody say it out loud) Nanoscale titanium dioxide particles.

I learned about the UV treatment while studying under Harry Lee Westmoreland Jr.s Living Water International. I have certification in water well drilling and multiple purification techniques of raw and contaminated water for third world country inhabitants. All part of my volunteer missionary field training that I took upon myself so I could be of use to people where ever I go. I'm a Christian, but not a flat liner, as some would mistakenly think.

Living Water International web site: http://www.water.cc

Here ya go, Xelif , here's one of many articles regarding UV treatment of water in simple plastic jugs. This particular article is taken from:

http://www.who.int/water_sanitation_health/dwq/wsh0207/en/index4.html

"Solar treatment by combined UV and thermal effects

Treatment to control waterborne microbial contaminants by exposure to sunlight in clear vessels that allows the combined germicidal effects of both UV radiation and heat also has been developed, evaluated and put into field practice (Acra et al., 1984; Conroy et al., 1996; 1996; 1999; Joyce et al., 1996; McGuigugan et al., 1998; 1999; Sommer et al., 1997; Wegelin and Sommer, 1998; Wegelin et al., 1994). A number of different solar treatment systems have been described, but one of the technically simplest and most practical and economical is the SODIS system developed by scientists at the Swiss Federal Agency for Environmental Science and Technology (EAWAG) and its many collaborators and partners.

The SODIS system consists of three basic steps: (1) removing solids from highly turbid (>30 NTU) water by settling or filtration, if necessary, (2) placing low turbidity (<30 NTU) water in clear plastic bottles of 1-2 liter volume (usually discarded beverage bottles and preferably painted black on one side), and (3) aerating (oxygenating) the water by vigorous shaking in contact with air, and (4) exposing the filled, aerated bottles to full sunlight for about 5 hours (or longer if only part sunlight). The water is exposed to UV radiation in sunlight, primarily UV-A and it becomes heated; both effects contribute to the inactivation of waterborne microbes. The system is suitable for treating small volumes of water (<10L), especially if the water has relatively low turbidity (<30 NTU).

Clear plastic bottles are considered preferable by some workers over glass because they are lighter, less likely to break, and less costly. Bottles made of polyethylene terephthlate (PET) are preferred to those made of polyvinylchloride (PVC), other plastics and most types of glass because they are less likely to leach harmful constituents into the water. In addition, they are lightweight, relatively unbreakable, chemically stable and not likely to impart tastes and odors to the water." (end article)

Brumfield wrote:
Also from: http://www.ciwem.org/policy/policies/chlorine_disinfection_of_water_supplies.asp

6. Generally, viruses are more resistant to chlorine than bacteria.

7. Harmful organisms can be shielded by particulates, therefore chlorination should be linked to a low water turbidity standard. This may require pre-treatment (filtration) processes if source waters are turbid.
________________________________________________________________

Xelif wrote: "Finally, the dead bacteria isn't going to hurt you. Viruses with disrupted genomes won't do much either. It is a bit creepy though. Just a bit of extra protein and carbohydrates though ;-)

Brumfield wrote: I prefer good Tequila with a dead Mescal worm over dead bacteria, but... each to his own favorite drink. <img src="/forums/images/graemlins/grin.gif" alt="" />

Xelif wrote: Bacteria that produces persistent toxins (such as botulism) aren't likely to be in our wild drinking sources."

Brumfield wrote: Unless you live where there are zero birds... ya better look here:

http://www.google.com/search?q=botulism+in+water&btnG=Search&hl=en

And from wild life: http://www.google.com/search?hl=en&a...G=Google+Search

Xelif wrote: I like my SteriPen and I use chlorine tablets as an alternative, just thought I might comment on this.

I use the BIG free SteraPen in the sky, (no batteries required) and I use chlorine dioxide too, but I can't help but wonder why quality water filter companies always mention that one of their filter's main purpose is to REMOVE chlorine? <img src="/forums/images/graemlins/confused.gif" alt="" /> So I chlorinate before filtering now. Brum <img src="/forums/images/graemlins/smile.gif" alt="" />
_________________________



Top
#89261 - 02/09/08 02:55 AM Re: water filter cross-over [Re: blazer209]
jasonlivy Offline
member

Registered: 01/02/04
Posts: 654
Loc: Colorado
It's true the benefits tablets have are that they are initially cheaper and weigh less for a typical week long trip, but...

I like my MIOX for a few reasons. One, the unit has never failed me. This is not to say that it won't ever fail, but I haven't had problems with it and I use it as my exclusive water treatment system when backpacking.

I believe that it does add an anti-microbial coating to the bottles, pots, and cups I use. I always add a small dose of MIOX when cleaning dishes. This is an added benefit over drops or pills. Since treating my Camelbak reservoir with MIOX it has stopped developing mold because I failed to let it dry out.

I've used it as a topical agent to treat minor wounds (abrasion injuries). It has effectively halted any infection from appearing in several injuries I've had on the trail. I actually carry it in my mtn bike pack because it works so well for me in case of a crash (and to treat water if I run out).

It doesn't taste bad when the proper dose is added and I've never gotten sick from backcountry water.

I also use it in the winter and believe it is one of the best solutions for winter water use. Instead of boiling water after melting the snow, I simply melt the snow to liquid and then add a dose of MIOX. I also add MIOX to my water bottle as I'm hiking and add snow along the way. This works very well for me and makes treating water a breeze in the winter. MIOX is not effected by super cold water. It will work in any temperature.

At 3 oz., it really isn't that big of an issue to carry. Yes, it's heavier than pills, but the benefits for me have proven it's worth it's weight. I've used pills and drops both and simply like using the MIOX better. When I add it to the water it disappears immediately and it is very visual to me that the solution mixes in better than a pill. I also think it makes the water taste less of chemical, again, if the proper dose is administered. Too often I hear people say they can taste the chemical or MIOX makes the water taste bad. Most of the time this is due to people putting in too much chemical or shaking the unit more than is needed resulting in too much salt saturation.

There are many who think the MIOX is over complicated and perhaps even overkill for a solo, ultralight backpacker. It is one of the best, and most overlooked, solutions for backcountry soloists in my opinion. To disregard it is to do yourself a disservice. Are there cheaper solutions? Yes. Are there lighter solutions? Yes. However, there isn't another water-treatment product that can also treat containers and be used as a topical agent. Nor one that does as much water as fast (compared to pumps) without worrying about running out of pills or drops. This makes it quite unique and worth considering.
_________________________
Believe, then you will Understand...

Top
#89262 - 02/09/08 03:09 PM Re: water filter cross-over - Weight versus safety [Re: Xelif]
Earthling Offline
member

Registered: 02/22/03
Posts: 3228
Loc: USA
Quote:
Quote:

To put it more simply, the particle-attached bacteria do not die as quickly, if at all, with chlorine treatment. You really should remove the particles and the micro size critters attached to the particles, not just kill some of them and then drink them down. They don't just simply dissipate into thin air when you chlorinate them, they are still there, and the now dead "bodies" of the bacteria and viruses are going into your system. <img src="/forums/images/graemlins/frown.gif" alt="" />

After UV treatment, ceramic filtering, and chlorine dioxide treatment of the water, I then carry 32 ounces of my water in a clear plastic bottle on top of my pack so it's exposed to the sun's UV rays most of the day. I always carry two 32 ounce bottles of ready-to-drink water. One in the pack and one on top receiving continued UV treatment, and rotate them out as I treat a new water supply.


I think you'll find that almost all plastic blocks UV quite well - the SteriPen in fact depends on this in order to prevent burning you with UV light. So, the plastic bag in sunlight doesn't do anything other than warm the water and degrade the plastic a little bit faster.

Also, the SteriPen suffers from the same problems that chlorine does - bacteria attached to large particles can be shielded from light. It also has taken this into account as the chlorine dioxide products have, as long as the water isn't too cloudy.

Finally, the dead bacteria isn't going to hurt you. Viruses with disrupted genomes won't do much either. It is a bit creepy though. Just a bit of extra protein and carbohydrates though ;-) Bacteria that produces persistent toxins (such as botulism) aren't likely to be in our wild drinking sources.

I like my SteriPen and I use chlorine tablets as an alternative, just thought I might comment on this.


Felix, do a search with google for SODIS and you'll find out you are wrong about solar sterilization <img src="/forums/images/graemlins/wink.gif" alt="" /> It's been in practice many years and is a recognized way to treat water.
_________________________
PEPPER SPRAY AIN'T BRAINS IN A CAN!

Top
#89263 - 02/09/08 03:19 PM Re: water filter cross-over - Weight versus safety [Re: Earthling]
Earthling Offline
member

Registered: 02/22/03
Posts: 3228
Loc: USA
<img src="/forums/images/graemlins/blush.gif" alt="" /> I just noticed Barry Brumfiled inserted Sodis in his post, does'nt hurt to know we BOTH studied with LWI <img src="/forums/images/graemlins/smirk.gif" alt="" /> been there, done that Brum <img src="/forums/images/graemlins/cool.gif" alt="" />

Jason Livy if you are in touch with the Platypus folks please find out for us if they know of SODIS, and if the Platy water bags are usuable in this regard. If so, Platypus might think of using this to their advantage in advertising their product; thus helping themselves and being supporters of the SODIS projects <img src="/forums/images/graemlins/cool.gif" alt="" />

Brum, you are a fountain of water knowledge <img src="/forums/images/graemlins/smirk.gif" alt="" />
_________________________
PEPPER SPRAY AIN'T BRAINS IN A CAN!

Top
#89264 - 02/10/08 12:01 AM Re: water filter cross-over-Plastic-UV-botulism [Re: Brumfield]
billk Offline
member

Registered: 08/20/03
Posts: 1196
Loc: Portland, Oregon
Quote:
Sorry, plastic does not block UV rays.


It depends on the plastic. Polycarbonate blocks UV fairly well. PET would be the choice for any type of solar water-treater.

It's my understanding that Giardia are not particularly affected by UV-A or UV-B, but would require UV-C radiation, which I think the Steri-pen must generate. There isn't much UV-C in sunlight by the time it reaches the ground.

Top
#89265 - 02/10/08 09:33 AM Re: water filter cross-over-Plastic-UV-botulism [Re: Brumfield]
Xelif Offline
member

Registered: 07/04/07
Posts: 241
Loc: Bay Area, California, USA
Alright, now we're getting into a good discussion! <img src="/forums/images/graemlins/smile.gif" alt="" />

I'm certainly familiar with using sunlight to disinfect water. I was just under the very strong impression that UV rays are blocked by most plastic. Mostly because of this off the Steripen site and from a little bit of UV experiments on the lab:

"UV-C will not pass through most materials. Drinking containers made from glass, ceramic, metal, and nearly all plastics block UV-C transmission. Also, the underside of the air/water interface in a water container acts as a very effective reflector for UV-C. As a result, when SteriPEN™’s lamp is immersed in virtually any drinking vessel, the UV-C is well contained. Note that SteriPEN™’s water sensors prevent it from operating unless the lamp is completely immersed.

While very few materials are transparent to UV-C, there are a small number of uncommon materials that are. These include optical grade quartz (the SteriPEN™ lamp material) and a few fluoropolymers in the Teflon family – both unlikely materials to be used for drinking containers."

http://www.steripen.com/faq.html

-- I am discussing specifically UV-C, apparently. So my source tells me at least <img src="/forums/images/graemlins/smile.gif" alt="" />
Your source speaks specifically of UV-A. This is an interesting divide.

Also, your source states the heating effects of the sun would be enough to deactivate 99.9% of organisms, leaving the effect of the UV (in my mind) somewhat up in the air. The UV has a contributory effect but is not the main sterilizing action from what I read, as long as the water peaked over 50 degrees C.

As far as botulism - it's only a concern with stagnant water. I don't drink from stagnant water. However, I realize that I'm in the minority when I tap from clear-running, non-stagnant, highly oxygenated mountain stream water <img src="/forums/images/graemlins/grin.gif" alt="" /> If I had to drink from jungle pools, aie!
_________________________
- John

Top
#89266 - 02/10/08 09:44 AM Re: water filter cross-over-Plastic-UV-botulism [Re: Xelif]
Xelif Offline
member

Registered: 07/04/07
Posts: 241
Loc: Bay Area, California, USA
I did a little more research and UV transmission is an entirely mixed bag. Acrylic as stated blocks most UV light, and the % of UV light absorbed by plastics such as polyethylene depends on the thickness, the coating, and the purity of the plastic. It DOES absorb and refract some UV light, the question is, how much? From what was linked earlier, the UV doesn't even need to penetrate - the water just needs to heat up. Also, which wavelengths are blocked best? The SteriPen folk believe that UV-C doesn't escape the container.

(edit) I really wish I hadn't graduated now, since I used a transmittance/absorbance machine almost every day in the lab and I could quickly and easily measure all of this data. Anyone else work in a lab?

(double edit now) You might have misunderstood me with the SteriPen - The Pen says you won't burn your skin or eyes from UV rays because the rays stop at the limit of the water bottle, not at any part of the Pen itself. The concern is that by staring at the lamp, while it's operating, you're giving yourself a NASTY UV burn. If plastic transmitted UV entirely, this is a problem. It either means that the plastic doesn't transmit the Pen's UV, or that the Pen's UV is just too low power to burn you.


Edited by Xelif (02/10/08 09:59 AM)
_________________________
- John

Top
#89267 - 02/10/08 10:00 AM Re: water filter cross-over-Plastic-UV-botulism [Re: Xelif]
Brumfield Offline
member

Registered: 12/23/07
Posts: 255
Loc: Expat from New Orleans, now in...
Hey, Xelif, good research, I've copied your info to my Water Purification folder. Thanks for sharing it here, and please keep us updated on what you come up with regarding proper or improper containers for UV treatment. I will pass your info on to the staff at Living Waters International. Peoples health and even their lives are at stake in the third world countries where every purification process must be made available to them asap.

Ya see that's why I like this group of people, nobody gets upset when you share, discuss, (or even disagree over) knowledge. In contrast, I'm in an ongoing battle over at HikingForums.net over whether you should carry a 44 magnum or a chili pepper spray in known bear and lion country. Seems kinda cut and dry to me, but some people just don't like guns to the point of being silly about it. And don't ya'll go start on me over here about it too! <img src="/forums/images/graemlins/smirk.gif" alt="" /> Brum
_________________________



Top
#89268 - 02/10/08 10:08 AM Re: water filter cross-over - Weight versus safety [Re: Earthling]
Xelif Offline
member

Registered: 07/04/07
Posts: 241
Loc: Bay Area, California, USA
Quote:
Jason Livy if you are in touch with the Platypus folks please find out for us if they know of SODIS, and if the Platy water bags are usuable in this regard. If so, Platypus might think of using this to their advantage in advertising their product; thus helping themselves and being supporters of the SODIS projects <img src="/forums/images/graemlins/cool.gif" alt="" />


I'm tempted to email SteriPen too, since they should have tested all of the common containers with regard to FULL UV transmittance (Not just their stated UV-C on the website). The actual usability of our common drinking containers for solar disinfection - this is a really important question, or at least I want to know the answer!

Thank you Brum for starting this discussion, it's been interesting so far.
_________________________
- John

Top
#89269 - 02/10/08 10:36 AM Re: water filter cross-over-Plastic-UV-botulism [Re: Brumfield]
Rick_D Offline
member

Registered: 01/06/02
Posts: 2939
Loc: NorCal
You're probably familiar with these folks:

http://www.solarcookers.org/

A really neat organization with an important mission.
_________________________
--Rick

Top
#89270 - 02/10/08 11:23 AM Re: water filter cross-over-Plastic-UV-botulism [Re: Brumfield]
Xelif Offline
member

Registered: 07/04/07
Posts: 241
Loc: Bay Area, California, USA
Quote:
Hey, Xelif, good research, I've copied your info to my Water Purification folder. Thanks for sharing it here, and please keep us updated on what you come up with regarding proper or improper containers for UV treatment. I will pass your info on to the staff at Living Waters International. Peoples health and even their lives are at stake in the third world countries where every purification process must be made available to them asap.

Ya see that's why I like this group of people, nobody gets upset when you share, discuss, (or even disagree over) knowledge.


I'm glad you're bringing it up with people who are in a position to use the information. (Slow-sand biofilters originally got me interested in water purification!)

I'm afraid all I did was muddy the waters, so to speak. I read the SODIS site itself, which has a wealth of referenced pdf files I'm just sinking my teeth into. First off, don't doubt the in-the-field SODIS tests that prove the method works. It's pretty convincing.

UV wavelengths extend from 400nm to, well, 1nm. UV-C is the shortest wavelength under discussion, and it's the best at disrupting DNA, etc. It's also, interestingly, blocked by ozone such that we don't see much at the surface. That's why the ozone layer is useful, and holes in it less useful. The ozone is at least partly generated via the energy released by UV interactions in the upper atmosphere.

The SteriPen supposedly pumps out primarily UV-C. Sunlight that reaches us is 98.7% UV-A, from 320nm to 400nm. (http://en.wikipedia.org/wiki/Ultraviolet)

To answer the question I originally brought up: None of our facts are wrong!

http://www.blackwell-synergy.com/links/doi/10.1046%2Fj.1365-2672.1998.00455.x

Page 2 has a depiction of UV absorption. The relevant information is that PET bottles absorb everything BELOW UV-A light. That means they absorb all the UV wavelengths that get soaked up by the ozone layer <img src="/forums/images/graemlins/grin.gif" alt="" /> In fact, almost all plastics do absorb UV-C light, just like the SteriPen states, and transmit UV-A light, like the SODIS site states.

SODIS states all plastics have, to some degree, UV absorbers such as plasticizers and dyes in them. PET bottles are best as you already know - and they've looked at the UV absorbance issue to some extent. For example, they warn that the older and more damaged the bottles are, the less UV gets through. That is, perhaps, the real issue with UV light and containers. I know that UV is the primary degrader of plastic and will eventually trash almost anything plastic left out in the sun, once it overwhelms any built-in dyes or absorbers.

Again, I'm really, really glad you brought all this up. I learned quite a bit - I just hope I'm managing to convey this in a halfway coherent form. This too is why I like this site, we pleasantly discuss things without rancor!

I'm going to have to think about how wonderful this method of disinfection is <img src="/forums/images/graemlins/laugh.gif" alt="" /> perhaps even lighter than the lightest ultralighter's dream <img src="/forums/images/graemlins/grin.gif" alt="" /> (don't tell them over on BPL)
_________________________
- John

Top
Page 1 of 3 1 2 3 >

Shout Box

Highest Quality Lightweight Down Sleeping Bags
 
Western Mountaineering Sleeping Bags
 
Lite Gear Talk - Featured Topics
Backcountry Discussion - Featured Topics
Make Your Own Gear - Featured Topics
Featured Photos
Spiderco Chaparral Pocketknife
David & Goliath
Also Testing
Trip Report with Photos
Seven Devils, Idaho
Oat Hill Mine Trail 2012
Dark Canyon - Utah
Who's Online
0 registered (), 160 Guests and 0 Spiders online.
Key: Admin, Global Mod, Mod
Newest Members
Noodles, McCrary, DanyBacky, Rashy Willia, WanderBison
13240 Registered Users
Forum Links
Disclaimer
Policies
Site Links
Backpacking.net
Lightweight Gear Store
Backpacking Book Store
Lightweight Zone
Hiking Essentials

Our long-time Sponsor, BackcountryGear.com - The leading source for ultralite/lightweight outdoor gear:

Backcountry Forum
 

Affiliate Disclaimer: This forum is an affiliate of BackcountryGear.com, Amazon.com, R.E.I. and others. The product links herein are linked to their sites. If you follow these links to make a purchase, we may get a small commission. This is our only source of support for these forums. Thanks.!
 
 

Since 1996 - the Original Backcountry Forum
Copyright © The Lightweight Backpacker & BackcountryForum