Biochar is a type of charcoal that is made from organic materials such as wood, agricultural waste, or coconut shells. It is a highly porous material that can be used to filter water by trapping impurities and contaminants.

To make a biochar water filter, you will need to create a container that can hold the biochar and allow water to flow through it. This can be done using a plastic or ceramic pot with a hole in the bottom, or by creating a filter using PVC pipe and a mesh screen.

To prepare the biochar, you will need to heat it to a high temperature in the absence of oxygen, a process known as pyrolysis. This can be done using a kiln or by creating a fire in a pit and covering it with a layer of soil. Once the biochar has been prepared, it can be placed in the filter container and used to filter water.