How to make a Water Filter

[preachtheWORD]

I got this from a wilderness survival blog. There are some typos, grammar issues, etc., but overall it is a good tutorial.

http://www.wilderness-survival-skills.com/how-to-make-a-water-filter.html

PS - If you don't have access to the plastic bottle or other container that the tutorial calls for, you can cut off the leg of your pants or the arm of your shirt/jacket and use it as the base for the filter. You will lose some water to leaks and evaporation, but it is beter than drinking nasty water.
Also, I would strongly reccommend adding a layer or two of charcoal to the filter to neutralize some of the nasty microorganisms that might be present.


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How to make a water filter
Knowing how to make a water filter is important, if the only water you can find is dirty muddy water. There are a number of different ways to make a water filter. One simple way is to use sand. Sand is nature's way of purifying water.


Simple sand water filter

1. To start with, you need a container. If you can find a large, empty can, use it. Punch 5-10 holes in the bottom of the can. A large plastic bottle is also fine. Cut the [bottom] end of the bottle off evenly. If there is no container available, you have to use what material that nature can provide, or that you brought with you.

If you find a birch tree, make a cone of birch bark. The cone will need to have a fairly small hole in the bottom. Tie the cone with rope to keep it from opening up.


2. First, you need to stop the sand to get out of the container.
Find some filter material you can place at the bottom. For instance:

• a couple of inches (centimeters) of pebbles.
• a grass mesh, make sure it’s nonpoisonous grass.
• or cotton material.


3. Add a layer of gravel. The main purpose of the gravel layer is to strengthen the filter material and prevent sand mixed with the water you get from the filter.


4. Fill your bottle or cone with sand.


5. Collect some water. Pour your collected water through the filter. Catch it in another container at the bottom. Look at the water that comes out of the filter. It should be clear. If not, you may have to pass the water through the filter more than once.


Safe water

Now you know how to make a water filter, but to get safe water to drink, you also have to purify your water. The water may still contain harmful bacteria that your filter did not remove.

To improve your water filter, add a layer of charcoal between the gravel and sand layer. Get charcoal from your fire, crush it, not to powder but just fine gravel size.

http://www.wilderness-survival-skills.com/images/how-to-make-a-waterfilter.jpg

[crashdive123]

While high on the cool factor, I'm not sure I would call it safe. The clearest, cleanest water around can still contain nasties like giardia and other microbes that could make their way through a filter with relatively large pores. It would be interesting to filter known contaminated water and then have it tested to see how it does.

[BENESSE]

Thanks Preach, I learned something new.
I'd probably boil the water in the end, just for good measure.

[your_comforting_company]

I think this is excellent. boiling is still a good idea to kill any little bugs that might get through. VERY handy knowledge to have. Thanks PTW!

[preachtheWORD]

Boiling would definitely be the best bet, no doubt at all. A filter like this one is mostly good for filtering out mud, silt, bugs, and other stuff that affects the palatability (i.e. "taste") of the water.

In the event that I had no way to boil the water, I would consider the charcoal layer to try to neutralize the nasties. I have even seen people mix charcoal right with the water, let it settle, and drink it just like that. Sounds rough to me, though. Charcoal is supposed to kill "belly worms," or so I'm told.

But if you have charcoal that likely means you have fire, which is half the equation for boiling water. If you can contrive some kind of vessel to hold the water, you're in business. Les Stroud boiled water in his hat once with hot rocks. I would be interested to learn about what you could make an improvised vessel out of. A deep depression in a rock might work. A hat or clothing made of leather or something else more or less waterproof that won't melt. What do you guys think?

[Trabitha]

Thanks!! This is totally knowledge useful to have!!

[your_comforting_company]

A hat or clothing made of leather or something else more or less waterproof that won't melt. What do you guys think?

Even a thick layer of clay in a sandy depression would hold water long enough to drop some hot rocks in for boiling. Anything that would hold the water long enough to drop the rocks in would be a great idea. I've seen skins used in some of my books. I'm learning to make pottery, but given the time it takes to actually make it, water would be needed first. if you had something to keep the hot rock from touching the bottom or sides of a plastic container, it would still work. fancy a quick woven basket of twigs or roots, just to hold the rock.. I see lots of possibilities.
Are those emergency blankets that look like tin-foil waterproof? Most folks keep one of those in their kit. It would make a good makeshift container.

[rwc1969]

It's a neat idea, but I wouldn't drink it unless I was dying of thirst. Boiling to kill the germs and some sort of charcoal filtration, even homeade, to limit the chemicals and improve taste is the only thing I will use unless in dire straits.

I struggle with this more than primitive fire.

[Rick]

It's a good post, Preacher but I side with everyone else on boiling. Charcoal will not kill anything.

[Pict]

http://img444.imageshack.us/img444/9067/img12120708614.jpg

I once made a large sand/charcoal filter to purify water for a camp property that housed about 120 people. This was a group effort and none of us had done it before so we kind of muddled our way through and made a few classic mistakes.

The end result was amazingly clear water but I wouldn't go as far as to call it safe at least not initially. The large sand filters form a layer of "scum" in the top of the sand that is actually a colony of highly predatory micro-organisms. This bio-layer eats any bacteria or other micro-organisms that pass through it. Eventually it will get so thick that it will impede water flow and has to be partially removed.

The dead remains of the victims and the waste of the predatory layer pass through the sand as particles that get trapped in the carbon matrix of the crushed charcoal layer. The result is water that is very clear and relatively free of pathogens. I would hesitate to say totally free. IMO the resulting water is like declaring a stream safe to drink from without treatment, you are taking a risk, though a much lower risk than if the water hadn't been filtered.

http://img94.imageshack.us/img94/6362/img12190636522.jpg

At the camp we were pumping water from a shallow well that was full of very fine yellow silt. The drinking water we used for the camp was passed through a ceramic filter element down in the kitchen after the sand filter. That simple low cost sand filter was a vast improvement over the unfiltered water.

Mac

[Rick]

In that scenario, the filtration process would vastly improve the life of your commercial filter, ceramic or otherwise.

[gryffynklm]

In regard to a vessel to boil water in, I saw someone boil water in a plastic soda bottle. I tried it and it worked. You have to keep the bottle above the flames. I used a string tied around the neck of the bottle and hung it from a stick. For a short term use its OK. I don't know about contaminants or toxins from the hot plastic getting into the water.

[welderguy]

In regard to a vessel to boil water in, I saw someone boil water in a plastic soda bottle. I tried it and it worked. You have to keep the bottle above the flames. I used a string tied around the neck of the bottle and hung it from a stick. For a short term use its OK. I don't know about contaminants or toxins from the hot plastic getting into the water.

I wouldnt think there would be any toxins from the plastic, concidering a lot of people put plastic in the micro.

[preachtheWORD]

I wouldnt think there would be any toxins from the plastic, concidering a lot of people put plastic in the micro.

Some plastics release bpa's (bisphenol-A) when heated. These chemicals have some potentially damaging long term effects. But that hardly matters if you are in a survival situaiton. If you need water bad enough, I suspect that you are not going to be terribly worried about chemicals that might cause problems years down the road.

A big thanks to Mac for the real world case study. Brother, I appreciate how you have done what most of us have only read about. I like the idea of using such a filter in tandem with a commercial filter. Good stuff.

Remember that this method of water filtration is for use in a survival scenario. I would not recommend it unless you were in desperate need of water. If I am getting dehydrated and the only water I've got is dirty, I would certainly try to filter it and drink it if my life was on the line. If I had any means to do it I would filter AND boil. That way it tastes much better and is clearer, and pathogen free.

[preachtheWORD]

Are those emergency blankets that look like tin-foil waterproof? Most folks keep one of those in their kit. It would make a good makeshift container.

I imagine that something like this would melt very quickly over a fire or even in contact with hot rocks. However, the hot rock method might just work if you kept the rocks off the plastic.

Here is a potential idea. If you have a space blanket or some other type of sheet plastic, you could dig a hole and line it with the plastic. Then you could insulate the plastic with something - a simple basket made of reeds or grass, birch bark, flat rocks, etc. - anything to keep the hot rocks off the plastic that will not further contaminate the water. Then you could pile in your hot rocks from the fire and get a boil going.

If you have sheet plastic you could also make a solar still, but that won't work as well in colder environments.

I appreciate all the input on this subject. Procurement of safe water is one of the most important skills necessary for long term survival, but also one of the more challenging.

[Rick]

You can toss the plastic bottle directly in the fire. It won't melt. The trick is to make certain the bottle is completely filled and there is NO air in the bottle. It's the air that causes the plastic to melt. The water will dissipate the heat and prevent the bottle from melting.

[whitewater4x4]

I have a ' Black Berky' water filter that the manufacture claims you can pour stagnant pond water into and come out with safe clean water . I haven't tried it yet . But if I was in a situation where I was dependent on that type of source of water I believe it would be worth my time to run the water through a similar sand /charcoal filtration just to save my commercial filters . Thanks for the info and ideas on how to do that .

[Rick]

You could use a bandana or any type of cloth as a pre-filter to get the junk and scum out of the water prior to actually filtering the water.