How to Make a Charcoal Filtration System for Survival

Cut the bottom section off a water bottle using your knife. Try to remove as little as possible to provide plenty of room for the filtration materials. Keep the bottom of the water bottle; you may find other uses for it.

Pour gravel into the opening you created in the water bottle. Create a small layer that stays in place when held with the top of the bottle facing downward. The gravel will help hold the other material in place while the filter is being used.

Add a layer of fresh grass on top of the gravel. Press the grass down firmly to create as compact a layer as you can. Fill the water bottle about one-sixth with grass.

Add sand on top of the grass layer. The sand helps remove small particles that are suspended in the water. If clean sand is not available, use dirt instead. The sand should fill about one-sixth of the water bottle.

Place the charcoal on top of the sand. The charcoal should not be in huge chunks or be ground into a powder. Use your knife or other tools to make the charcoal about gravel sized. Fill the water bottle about one-sixth of the way with charcoal.

Repeat steps 3 through 5 by adding layers of filtering material until the water bottle is full.

Pour water into the filter slowly while holding a cup or pan beneath the filter to capture the water. The water should move very slowly through the filter if you packed everything tight enough. If the water flows through too quickly, pack the material down inside the filter and add additional layers if you can.