How to make a water filter using crushed up bone?

Making a water filter with crushed bone is an ancient and effective method that leverages bone's natural filtration properties. The bone char, created from heating and crushing bones, is porous and can absorb contaminants like fluoride, heavy metals, and some bacteria. Here’s a simple guide to making a water filter using crushed bones:

Materials Needed

• Animal bones (cattle bones work well, and they need to be thoroughly cleaned)
• A metal container or grill for charring the bones
• A hammer or mortar and pestle for crushing the bones
• Sand (optional, for additional filtration)
• Gravel or small pebbles (optional, for layering)
• Container with a small hole (for filtering, like a plastic bottle or bucket)
• Cloth or coffee filter (to prevent particles from passing through)

Steps

1. Prepare the Bones

• Clean the bones thoroughly to remove any remaining meat or fat.
• Boil them in water to remove residual oils and contaminants.
• Let the bones dry completely after cleaning.

2. Char the Bones

• Place the bones on a metal container or grill.
• Heat the bones at a high temperature (around 500–900°F or 260–482°C) to turn them into bone char. This process drives off organic material and creates a porous structure.
• This can be done in a wood fire, an oven, or a kiln if available.
• Let the charred bones cool completely after heating.

3. Crush the Bones 

• Use a hammer or mortar and pestle to crush the charred bones into fine pieces. The finer the bone char, the better the filtration.

4. Build the Filter

• In a container (such as a plastic bottle cut in half), place a cloth or coffee filter at the bottom to hold the crushed bone char in place.
• Layer the crushed bone char on top of the cloth. Aim for about 2–3 inches (5–7 cm) of bone char.
• Optionally, add layers of sand and gravel on top of the bone char to improve filtration. The gravel and sand act as pre-filters, removing larger particles before water reaches the bone char.

5. Filter the Water

• Slowly pour water into the filter and allow it to pass through the layers.
• The bone char will absorb contaminants as the water flows through.
• Collect the filtered water from the bottom container.

Important Notes

• Bone char filters are great for removing fluoride, heavy metals, and some bacteria but may not remove all pathogens. For safe drinking water, further purification (e.g., boiling) is recommended.
• Use only animal bones that are free of chemicals, as bones from animals treated with chemicals or drugs may leach unwanted substances into the water.
• Replace the bone char regularly, as it will eventually become saturated with contaminants.