Sometimes your only source is going to resemble soup more than water. Simply boiling isn't gonna be enough. So what do you do in these situations?

Well there is a method that is pretty simple, and relatively easy to find the materials for. The two hardest, if you can call them that, are two 2 liter bottles (or larger) and cheese cloth or gauze pad. The third item is Twine/string/rubber band/etc...

Part I

Assuming you have a knife/scissors.

On the first bottle cut the base off, leaving as much as you can of the body of the bottle as well as the neck/opening intact. Place cheese cloth/gauze over the opening and secure with twine or other suggested items.

On the second bottle do the opposite. Cut the upper part, including the neck and opening off. Leaving as much of the body and base as you can.

Place bottle one, opening/neck down into the second bottle so that you have a funnel leading to an empty base. Sometimes they fit snuggly together, but if not, on the large opening of your funnel cut a slit not more then a 1/2 in several times around the bottle. Fold some of the flaps in, bend some if the flaps out. This should help secure them together.

Part II

Filling material.

Crush up charcoal from a previous days fire. Coals must be dry and cold. (do not use charcoal briquettes for grilling) you want them to be of course granules, slightly bigger then sand. We don't want powder. Place into funnel about 3 in thick.

Next add between 1/2-3/4 in. of sand. Above sand add about an inch of small gravel. Repeat sand layer. Then again with a second gravel layer.

And your done.

Slowly add water to allow it to seep through.

After this boil the water as a final safeguard.