The third and most important item is the charcoal. This is the part of the filter that removes the most impurities from the water. In order to get charcoal in the wild, you must make it yourself. The first step in making charcoal is building a fire. Once you have your fire, put one large log on the fire and wait until the log is totally burned but has not turned into ash. Using another stick, take the burn pieces of charcoal off of the log. Keep these pieces safe until the building process.
The next materials include stones and gravel. If you are in an area that does not have sand, then do not waste your time looking for it because it is not the most important part of the filter. You only need about a handful off each of these materials. The last material is a type of cloth. Although it is not found in the wild, cloth may be the easiest item to retrieve on this list.
After collecting the materials, we can start build the filter. It is actually very simple and easy. The first thing that you should do is roll the bark into a cone and use your knife to poke a hole through the overlapping part. String the leaf or branch that you picked earlier through the hole and tie off the end using a square knot.
Now, take your pieces of charcoal and put them in the center of the piece of cloth you have. Now bring all the corners of the cloth together so the charcoal sits in the bottom. Now, covering the charcoal, use your hand to smash it into a powder. Put the part with charcoal into the cone and spread out the corners so you can see the charcoal.
Pile on the gravel and then the rocks and your filter is set to go.
After that, boil the water For purification. We will need an area where clay is under the soil. We will use the clay to line the hole in the ground so that no water leaks into the earth. This is pretty simple, dig two holes, one for boiling and one to get clay. Take the clay and add a little bit of water to it so you can apply it to the hole. Seal off all the dirt. Now you can pour water into it and get your fire going along side it. You will need to find dry rocks to do this. Put a few rocks in the fire and once they have been in the fire for a while, you can put them into your water using another two sticks. You know its boiling when its bubbling.
Now you know how to put together a water filter in the wild. But this method for water purification is for SURVIVAL CONDITIONS ONLY, and it is not the best method of purifying water if you are near civilization. During “normal” times, find and install a qualified water filter for your drinking water.