Water Filtration With a Tree Branch 205
Taco Cowboy writes "Dirty water is a major cause of mortality in the developing world. 'The most common water-borne pathogens are bacteria (e.g. Escherichia coli, Salmonella typhi, Vibrio cholerae), viruses (e.g. adenoviruses, enteroviruses, hepatitis, rotavirus), and protozoa (e.g. giardia). These pathogens cause child mortality and also contribute to malnutrition and stunted growth of children.' People have been working on engineering cheaper and cheaper filtration systems for years, but now a group of researchers has found a promising and simple solution: a tree branch. 'Approximately 3 cm^3 of sapwood can filter water at the rate of several liters per day, sufficient to meet the clean drinking water needs of one person.' 'Before experimenting with contaminated water, the group used water mixed with red ink particles ranging from 70 to 500 nanometers in size. After all the liquid passed through, the researchers sliced the sapwood in half lengthwise, and observed that much of the red dye was contained within the very top layers of the wood, while the filtrate, or filtered water, was clear. This experiment showed that sapwood is naturally able to filter out particles bigger than about 70 nanometers.' The team tested E. coli-contaminated water, and the branch was able to filter out 99 percent of the bacterial cells."
First time? (Score:4, Insightful)
What I'm wondering, is why no other society, that we know of, has discovered this low-tech, yet seemingly incredibly useful thing previously?
Re: (Score:2)
If this is true, then this is a really profound discovery that could help millions of people. What I'm wondering, is why no other society, that we know of, has discovered this low-tech, yet seemingly incredibly useful thing previously?
Maybe because all of the other materials and equipment required to make it work.
Re:First time? (Score:5, Funny)
If this is true, then this is a really profound discovery that could help millions of people.
What I'm wondering, is why no other society, that we know of, has discovered this low-tech, yet seemingly incredibly useful thing previously?
Maybe because all of the other materials and equipment required to make it work.
You mean like some sort of cutting implement to cut down the branch?
I think the hatchet was invented at least 10 years ago?
Re: (Score:2)
Maybe because all of the other materials and equipment required to make it work.
Fill a metal container with water, plug the opening with wood, heat, collect and condense steam.
My brother and I used to do that sort of thing as kids (except the last bit). However if you take the wood out of the above method you have a normal still, villager's don't build stills because they require too much fuel.
Another simple idea that I saw on Aussie TV a while back was simply to mix a bit of charcoal into clay and make it into a pot. The resulting pot is porous, fill it with raw sewerage and the w
Re:First time? (Score:5, Insightful)
Ideas can be publicized, studied in more detail, or put to good use, without being truly new.
Re:First time? (Score:4, Interesting)
24So the people grumbled at Moses, saying, "What shall we drink?" 25Then he cried out to the LORD, and the LORD showed him a tree; and he threw it into the waters, and the waters became sweet.
Re:First time? (Score:5, Funny)
1) Someone mentions a new discovery.
2) Find a passage in the Bible containing the (rather common) keywords, without actually using your brain to check that the passage has identical informational value.
3) ???
4) Prophet!
Re: (Score:2)
Somebody Probably Thought of That (Score:5, Insightful)
"Somebody probably thought of that" is more likely to be untrue than true. You probably are the first person to think of that. And even if you aren't you might be the first person to act on the idea. And even if you aren't you might be the first person to succeed where others have failed. And even if you aren't, you might learn something. So don't ever say that, "somebody probably thought of that."
Filtering water through wafers of wood is not obvious to me. I do engineering for a living. If you are wondering why no one ever discovered something before, go back to paragraph one and repeat.
Re:Somebody Probably Thought of That (Score:5, Insightful)
Tapping water from a tree a well known technique (Score:2)
I believe archaeologists have found ancient village sites with a pit filled with layers of sand, charcoal, wood and plant fibers (crushed material, pounded on rocks ?), etc. It was the village water purification system. Not exactly wafers but interestingly close.
So with respect to things that humanity has been doing for millions of years, getting clean water in this case, I tend to be a little more open
Re: (Score:2)
Re: (Score:3)
Re: (Score:2)
The Cat Flap. Douglas Adams (in I think Dirk Gently's Holistic Detective Agency) makes the comment of consider the cat flap, that door within a door. When the first person invented it, everyone else who thought about it said, yeah, well, I could have thought of that...except they didn't.
Re:First time? (Score:5, Informative)
If this is true, then this is a really profound discovery that could help millions of people.
What I'm wondering, is why no other society, that we know of, has discovered this low-tech, yet seemingly incredibly useful thing previously?
Well, I learned this technique as part of my Aboriginal American studies when I was growing up -- I think it's more likely that our western culture has "lost" this knowledge than that nobody has discovered it before.
Re: (Score:2)
Maybe it was shunned in the pursuit of making money ? LOL
Re: (Score:2)
This is not something you could set up, let sit in storage for a few weeks, pull it out and expect it to be effective.
It looks like it would be most effective on a small but not personal level. With a small group you could filter enough water to keep the wood damp for a long time, replacing the "filter" as needed. So
Re: (Score:2)
Sounds great for villages in developing countries, but it doesn't look like it would scale very well.
Um, isn't that the whole idea here? I don't think anyone's thinking of using tree branch slices for commercial-quality water filtration in Western countries. No one's going to start selling tree branch slice filters for Samsung and GE refrigerators and Pur faucet adapters. The whole idea here is to come up with ultra-cheap, low-tech, but effective methods of improving quality of life and health and sanita
Re:First time? (Score:4, Insightful)
When people have to hike for miles to find wood for cooking fires, I'm not sure that fresh cut wood is all that practical.
Re: (Score:3)
If you have access to trees, plastic tubing, and some kind of sealant, then yeah, you probably have access to other methods... like boiling. I'm not saying this has no use, but in the crowded conditions where clean water is most needed it probably isn't practical as presented.
Re: (Score:3)
There are other methods like slow sand filter, bio sand filter, and solar disinfection.
https://en.wikipedia.org/wiki/... [wikipedia.org]
https://en.wikipedia.org/wiki/... [wikipedia.org]
https://en.wikipedia.org/wiki/... [wikipedia.org]
Thou with SODIS use glass if you can do to the endocrine disruptors BPA and BPS
being in most plastic bottles.
https://en.wikipedia.org/wiki/... [wikipedia.org]
Re: (Score:2)
Sadly, glass is less effective because of its tendency to block UV. You have to let the water get up to temp in a glass bottle. I bought a cute little doodad with some kind of phase change wax sealed in glass that changes color (sort of) when the water reaches an adequate temperature.
Re: (Score:2)
Thou with SODIS use glass if you can do to the endocrine disruptors BPA and BPS being in most plastic bottles.
The very Wikipedia article you linked to says to use PTE bottles, because some glass bottles will absorb the UV before it gets to the water, and that the leaching of material from plastic bottles into the water has been studied and found not to be of concern.
Re:First time? (Score:5, Insightful)
If this is true, then this is a really profound discovery that could help millions of people.
What I'm wondering, is why no other society, that we know of, has discovered this low-tech, yet seemingly incredibly useful thing previously?
For one thing, it doesn't filter viruses, so maybe it's already been evaluated and dicarded as a good solution. From TFA:
Karnik says sapwood likely can filter most types of bacteria, the smallest of which measure about 200 nanometers. However, the filter probably cannot trap most viruses, which are much smaller in size.
So it's of limited utility, since, as the summary says, common pathogens include viruses (e.g. adenoviruses, enteroviruses, hepatitis, rotavirus) -- for example, rotavirus is around 30nm in size, less than half the effective filtering size of the wood.
So the water will probably still need chemical or UV treatment after filtering.
Plus it's not clear how well it would work in the field, when the scientists built their filter:
They cut small sections of sapwood measuring about an inch long and half an inch wide, and mounted each in plastic tubing, sealed with epoxy and secured with clamps.
So while wood as a filter medium sounds attractive, if the user needs specialized equipment to get it to make a safe, water-tight seal, maybe it's not as useful in an area with limited resources.
Lack of information (Score:5, Informative)
You can make a pretty decent biofilter simply by folding a piece of cotton cloth such as an old Indian sari a few times - it'll remove 99% of cholera and many other particularly nasty infectious agents. Yet people are still getting infected because they don't know about the simple solution - it's not a technology problem, it's a public information problem. And spreading public service announcements among a population where where most people don't even own a radio is a serious challenge. Doable, but expensive and there's no profit in it, so it usually falls to small humanitarian organizations that do their best to make the information go viral, and usually fail. Getting a meme to go viral is a lot more difficult when it can only spread through face-to-face interactions.
Re: (Score:2)
Most common pathogens (Score:2)
The most common water-borne pathogens are bacteria ...,viruses ...,and protozoa
Well, that pretty much covers it I guess. I was surprised the kingdom animalia didn't make it on the list, but then hey, I'm no biologist.
In all seriousness, this is a very interesting discovery and I hope it leads to cheap and widely accessible drinking water.
Re: (Score:2, Insightful)
...I hope it leads to cheap and widely accessible drinking water.
Coca Cola and Pepsi will do all they can to make sure that never happens. Water is big business. That is why access is so difficult.
Re: (Score:2)
Access to the sky for water is free in most states though a few totalitarian
nut job states like Colorado make it illegal to collect water that falls on your roof....
Re: (Score:2)
So that it flows back down into the water supply and keeps downstream places hydrated.
Re: (Score:2)
There's a big difference between collecting rainwater on your roof and damming a stream or river. There's no valid reason to restrict the former, there's lots of good reasons to restrict the latter.
Re: (Score:2)
In fact, there are places that regulate the opposite. If your property is paved over and does not absorb enough rainwater and dumps it into the storm drain system, there are extra fines/taxes.
Re: (Score:2)
That makes sense; the storm drain system is only designed to handle so much water flow.
Fining people for collecting rainwater in their houses makes no sense: the water is going to run onto the ground and be absorbed by the ground anyway. By collecting it and using it for your house's water systems (showers, toilets, etc.), all you're doing is adding a short delay to that process, before it goes into your septic system (assuming a rural house here; city-dwellers don't typically try to collect rainwater), an
Re: Most common pathogens (Score:4, Insightful)
Re: (Score:2)
We can never let that happen. As a member of PETP, I demand to know whether the trees were properly anesthetized prior to being bled alive, used without consent as subjects for scientific testing, and mutilated. If these trees were young, were their parents consulted? Color me outraged.
Re:Most common pathogens (Score:5, Funny)
Water-borne pathogens in the kingdom Animalia are usually called "predators" rather than "pathogens". But yes, pathogens such as A. Mississippiensis can be filtered from the water with an appropriately-sized tree branch.
Take That, Capitalists! (Score:2)
HA!
I always love it when somebody discovers a natural, free way to accomplish a goal that someone else wants to sell me a solution to.
Re:Take That, Capitalists! (Score:5, Funny)
Re:Take That, Capitalists! (Score:5, Insightful)
Filtering out "99%" of harmful bacteria may be like filtering out 99% of bullets fired at you....
So, I take it you're not a fan of Lysol or Purell?
What a silly thing to say; as if not filtering 99% of something harmful is a better idea...
Re: (Score:2)
In the case of Purell, its Triclosan that is an issue.
http://www.huffingtonpost.com/... [huffingtonpost.com]
Maybe they have removed it, maybe not.
https://en.wikipedia.org/wiki/... [wikipedia.org]
On its own its not the worst threat in the environment, but when you add it along with
others the combined threat is pretty bad and would explain the reduction of quality of
health compared to some other nations.
Re: (Score:2)
I think you missed the point - it's less about what's in Purell, and more about the whole "killing 99% of germs is better than not killing any of them" concept.
Re: (Score:2)
What a silly thing to say; as if not filtering 99% of something harmful is a better idea...
OP does have a quite valid point...I worked in water testing lab years ago so I have some experience with this. The EPA standard [epa.gov] for coliform in drinking water is zero, that is to say one e. coli bacteria in a water sample (usually 100 ml) means the water is contaminated. (And generally when water is contaminated, there will be far more than just one bacteria per 100 ml.)
So while, yes, removing 99% of the bacterial load is better than not, as a general rule a 99% effective "decontamination" process still
Re: (Score:2)
Regarding OP's analogy, if someone fired 100 bullets at me, and I had a way to automatically block 99 of them, I'd have to be an idiot to not use that method just because 1 bullet might get through.
Yes, I might still get shot, but at least I won't be riddled with holes.
Re: (Score:2)
Yes, but, the OP didn't say that one shouldn't use the method...those were *your* words and *your* assumption. The analogy simply points out that '99% removal' may not be adequate in this particular case.
Infection rate (Score:2)
What I've always wondered is, how does the infection rate relate to the number of bacteria? Is "it only takes one" a true statement? I.e., if just one bacterium slips through the filter, are you as likely to get an infection as if a million slipped through? Or is there some "critical number" of bacteria, below which a normal immune system can easily handle things, but above which infection tends to set in?
Re: (Score:2)
It depends on a lot of factors. First of all, for e. coli, most strains are harmless and so 1 or 10,000 of those cells won't really affect you. However, the greater the number you ingest, the greater the chances that you'll get one of the pathogenic strains. For someone with a normal immune system, I'd expect the chance of just one cell causing an infection is exceedingly small, but for someone with compromised immunity it would obviously be much higher.
But as I mentioned upthread, when water is contam
Re: (Score:3)
Maybe so, but do you blend bleach into all of your drinking water?
Re: (Score:3)
Maybe so, but do you blend bleach into all of your drinking water?
What, you don't?
If hydrating doesn't result in debilitating stomach cramps, you're doing something wrong, bro.
Re: (Score:2)
I've actually heard that a very small amount isn't a bad idea for long-term storage of emergency water. But it just seems too weird. Like burning out a chest cold w/ cigars or flushing through a stomach virus with Drano.
Re: (Score:2)
I've actually heard that a very small amount isn't a bad idea for long-term storage of emergency water.
From the CDC: [cdc.gov]
Re: (Score:2)
I don't but my town water facility does. Fair chance yours does, too.
They put chlorine in the water. Bleach contains substances besides chlorine that are more hazardous, even in small amounts.
Re: (Score:2)
Methinks you've got a few extra 9s in there, Chlorox only claims their bleach kills 99.9 percent of germs and bacteria, and that only adds ~3 generations to get back to 1% of the original population, compared to the ~7 needed to get from 1% back to 100%. And bacteria come by the millions, anything short of 100% effectiveness means you will be infected.
Fortunately, our bodies are not without their own defenses, and 99% buys you at least an extra day or two for your immune system to stumble upon an effective
Re: (Score:2)
No, I am not a fan of Lysol or Purell to decontaminate drinking water.
"Acceptable" residual bacterial counts in drinking water are not the same thing as acceptable residual counts after washing your hands.
I didn't know you had a set of portable goalposts...
Re: (Score:3)
Yes, it is. And I'd rather be hit by the one bullet than all 100 of them. I'd stand a much better chance of living.
Especially since there's a much better chance of your body's natural defenses defeating that 1%
Re: (Score:2)
Bullets don't divide and multiply every 15-20 minutes while just sitting there in the air waiting to hit you.
Or in the case of bacteria, while swimming there in the water you're still slowly filtering.
However, this method is probably still useful for filtering out various other harmful particles found in water.
And if you got wood and tools to construct a filtering apparatus, you can probably boil that filtered water too.
Yeah, yeah, I know, they were testing this as a solution for people who can't afford bur
Re: (Score:2)
And if you got wood and tools to construct a filtering apparatus, you can probably boil that filtered water too.
As TFA points out, the problem with boiling water is fuel consumption, whereas filtering through a cold tree branch requires no fuel whatsoever, other than the physical energy exerted by the tree branch user.
Re: (Score:3)
99% is great! (Score:2)
Re: (Score:2)
No, but if you had 100 bullets coming at you and had the opportunity to hold a shield that would catch 99 of the bullets, would you really refuse holding it because it wouldn't catch 100% of the bullets? You don't stop the bullets by saying "don't come at me until I have a shield that will stop all the bullets."
Re: (Score:2)
Your immune system is virtually bullet proof under those circumstances
Re:Take That, Capitalists! (Score:5, Funny)
Re: (Score:2)
Well played, Rhacman.
Re: (Score:2)
There's already a company selling a variant of this.... using a coconut shell based filtration system working on the same principle. www.drinksoma.com
Re: (Score:2)
Well, it's not completely free -- someone likely owns those trees. And people living in desert regions of the world don't have easy access to sapwood -- nor do people in parts of the world where the sapwood is of the wrong consistency in local trees (hardwoods, for example).
Re: (Score:2)
Well, it's not completely free -- someone likely owns those trees. And people living in desert regions of the world don't have easy access to sapwood -- nor do people in parts of the world where the sapwood is of the wrong consistency in local trees (hardwoods, for example).
Yea, guess you've got me - I mean, it's not like a person can just, you know, stick a seed in the ground, tend to it properly, and bada-bing-bada-boom, a tree will grow, right?
Re: Take That, Capitalists! (Score:2)
Re: (Score:2)
Most people need clean water on a regular basis and cannot accommodate waiting for a tree to grow to quench their thirst.
Where did I say it was a perfect solution? At least it's something more than "dur, you have to buy trees from someone."
Do you have anything relevant and useful to add, or did you just come here to whine that the solution I offered isn't perfect?
Re: (Score:2)
...stick a seed in the ground...
Have you checked the price of tree-worthy ground lately? Or materials to provide nutrients and hydration to said ground? I started digging a nursery on Broadway, but the local traffickers got all bent out of shape. Do you have a cow? Because I have a pocket full of very young trees I'd like to trade you.
Re: (Score:2)
...stick a seed in the ground...
Have you checked the price of tree-worthy ground lately? Or materials to provide nutrients and hydration to said ground? I started digging a nursery on Broadway, but the local traffickers got all bent out of shape. Do you have a cow? Because I have a pocket full of very young trees I'd like to trade you.
Sorry, all full up on trees (half my state is a national forest, after all); although, if you have a few hundred feet of copper wire to spare, I'm sure we could work out some kind of barter.
Re: (Score:2)
Only a few hundred? Great! I'll get them delivered. Just set up a small box down-town with a charging socket on a post and a sign that says, "Free for the first 2 months - Leaf and Volt owners only!" That way my delivery people know that they're bringing you the wire for free. They'll drive the wire to your collection station and attach them to let you know they're ready to be harvested. I'll throw in some batteries too if you're willing to invest in a pry-bar.
As far as the delivery of the cow... I'm
Re: (Score:2)
This conversation went from sardonic to hilarious in a hurry, didn't it?
Re: (Score:2)
I prefer hilarity, but hey - I'm open minded. I can swing both ways. =)
Re: (Score:2)
A) How long is the person supposed to go without water while the tree grows? Or should the person drink the dirty water and possibly die before the tree is grown
B) That assumes a tree of the right type will grow where the person is located. If the local climate is not conducive to trees growing, then the person will have a long wait.
C) Assumes that the person will have the time and energy to "tend it properly". If one is spending 12 hours a day just to survive, tending a tree may not be possible.
D) Assumes the person has access to enough land to grow a tree in the first place. There is not a lot of places to grow trees in favelas and urban slums in the second and third world.
I don't see you coming up with any better ideas.
If it is so quick and easy because "stick a seed in the ground, tend to it properly, and bada-bing-bada-boom, a tree will grow", please grow one and let us know how long it takes.
Depends on the tree, obviously.
Re: (Score:2)
In other words, you don't see the flaw in your logic and don't like it when people point it out. It is like you have no experience in the real world.
"Pointing out the flaw in [someone's] logic," without offering anything other than that, is pretty pointless.
Unless, of course, your point is to be intentionally inflammatory, or to derail the conversation.
So, do you have a better idea? Will you tell us, or just keep on trolling with snarky ad hominem attacks? The world sits on razor's edge awaiting your response.
Re: (Score:2)
So you can get a filter in, say, 30 years? Lot of good that is going to do the family having to drink contaminated water tomorrow.
Perhaps they could barter for the wood they need. I don't know, but what I do know is "your idea isn't perfect, therefore it's a bad idea" is the thought process of a complete, abject moron.
Re: (Score:2)
And people living in desert regions of the world don't have easy access to sapwood...
People living in desert regions probably get their water from wells, which is relatively clean.
People living in more temperate regions where there is excess water are more likely to drink the dirty surface runoff. It's not that water is scarce, it's that it is dirty. Where I live, trees are weeds... I have to pull tree sprouts up by the dozens every year to keep my yard from turning into a rainforest. But we don't drin
Re: (Score:2)
somebody discovers a natural, free way to accomplish a goal
Really? Doesn't look all that free or natural to me:
1 inch-long sections were cut from a branch with approximately 1 cm diameter. The bark and cambium were peeled off, and the piece was mounted at the end of a tube and sealed with epoxy. The filters were flushed with 10 mL of deionized water before experiments. Care was taken to avoid drying of the filter.
Approximately 5 mL of deionized water or solution was placed in the tube. Pressure was supplied using a nitrogen tank with a pressure regulator. For filtration experiments, 5 psi (34.5 kPa) pressure was used.
Re: (Score:2)
So... $0.25 worth of epoxy? I don't see anything there that couldn't be done for free or, at the very worst, an incredibly low cost. You can pressurize a container with a make-shift hand pump, for example.
Re: (Score:2)
Re: (Score:2)
You really need a good seal to maintain pressure and make it tight enough to keep out microorganisms. It's hard to see how you can do this for free.
Certainly there are scaling problems with this too.
Another thing about this process is that like many ideas for cleaning water it lacks the ability to keep the water clean after it's processed. The residual effect of chlorine and related materials is one of the reasons chlorine is so tough to beat - after you apply it a residual of hypochlorous acid keeps the wa
Re: (Score:2)
I always love it when somebody discovers a natural, free way to accomplish a goal that someone else wants to sell me a solution to.
This filtration requires use of Monsanto's patented PureWood trees. Use of any other wood type for filtration will result in severe DMCA penalties.
Re: (Score:2)
This process is also patented, use of wood for filtration will require royalty payments or hefty penalties.
Re: (Score:2)
Well, at least this will help people living in slums and favelas in places like Manila, Rio, etc. because sapwood is free, cheap, and highly available there. Oh.... wait...
Re: (Score:2)
Yeah! Now all these people in the developing world have to do is chop down even more trees. Deforestation, YAY!. Oh, wait....
Well, at least this will help people living in slums and favelas in places like Manila, Rio, etc. because sapwood is free, cheap, and highly available there. Oh.... wait...
OK, so are you going to suggest a better idea, or just troll (then whine in your sig when your troll-y posts are appropriately modded)?
Re: (Score:2)
By the way, your original comment is very "troll-y". You are the pot calling the kettle black.
Yea, no it's not.
But hey, you just keep telling yourself that so you can feel justified in being a d-bag who doesn't have anything worthwhile to contribute to the conversation.
'Cuz that seems to be working out so well for you.
Time to watch Nausicaä again (Score:4, Informative)
"It's so beautiful. It's hard to believe these spores could kill me."
Pour water through the branch? (Score:2, Interesting)
Exactly how do you pour water THROUGH a branch? This sounds like the old boyscout prank of expecting someone to push a rope. Or maybe this is more like herding cats?
Re: (Score:2)
I would expect that you'd need something like a large pottery vase or jar with a tapered hole in the bottom. You cut the length of sapwood, wrap one end with a fiber cord until you can push it down into the hole and have it fit tightly with the branch sticking out the bottom (a rubber gasket would be better, but may not be readily available), then pour your 'raw' water into the vase and hang it over another container to catch the water that passes through the branch. A higher-tech solution would use some so
Re: (Score:2)
Sub-technological cultures... that would be things like communities of apes, right? Wait, no. Even they have a degree of language and other culturally-transmitted technology such as termite-fishing with sticks.
Low-tech yes, sub-tech no. Don't contribute to the trap of thinking technology = modern high-tech technology. Language, money, stone axes, etc. all had their heyday as high technology, and assuming we don't wipe ourselves out there will come a day when today's smartphones and airplanes look every b
The article refers to an article with pictures (Score:4, Informative)
In brief, find a stalk of sappy wood -- my Dad showed us every spring how to make a whistle out of alder branches that look what the picture shows -- peel it, whittle it to size and then plug it into the end of a tube and gravity feed water through it.
simple...ank
Re: (Score:2)
Re: (Score:2)
Re: (Score:2)
Re: (Score:2)
Is a hopper a funnel? I could see that working.
Or a bucket? I'm assuming this is only going to be gravity fed, branch isn't going to move it uphill.
Wooden chopping boards. (Score:5, Informative)
Trees are great at dealing with bacteria.
http://faculty.vetmed.ucdavis.... [ucdavis.edu]
Re: (Score:2)
That's why I let my dog lick my plastic cutting boards clean and then run them through the dishwasher with the "heat dry" and "sanitize" settings.
The dog licking is amazing. If I cut red meat on it and wash it in the dishwasher with the above settings, the board is still faintly stained. But when the dog is done, even before washing, there is NO staining.
So far, nobody here has gotten sick...
Re: (Score:2)
Try giving it a rinse with white vinegar first instead of letting the dog lick it.
Re: (Score:2)
FTFY, or at least I hope so.
It's " 99.9% of bacteria" not 99% (Score:2)
Bacteria filtration is awesome for the wood filters.
Also, one has to be very careful not to let the wood dry out, because drying out damages the ability of the wood to pull water through, and if dried wood DOES let water through, it isn't filtered.
--PM
Re: (Score:2)