How to make a filter
A plant pot with a plug of cotton wool in the bottom and a layer of sand a few inches deep makes a satisfactory filter for many purposes.
Make some muddy water by stirring earth in a dish of water. Pour the water into the filter and catch it in a clear glass as it drips out. See if you can better the filter by building it up with alternate layers of sand and powdered charcoal. like a filter will work very well for clarifying water before it is boiled for drinking purposes.