Water filter
Aim:
To understand the importance of clean water.
You will need:
Large empty plastic bottles, scissors, filter materials (e.g. sand, small stones, pebbles), water and soil, empty containers (e.g. glass jars).
Duration:
45 minutes
It is essential that we drink enough water every day to keep healthy. The recommended amount is about 8 glasses a day. In richer countries water comes out of taps, and is safe to drink. Unfortunately many poorer people are not as lucky, and the water they collect is often dirty and unsafe.
Make your own water filter, to try cleaning muddy water. Use an empty plastic bottle. Turn it upside down, and cut off the base (using sharp scissors). Put in layers of different materials to filter the water. At the bottom you could put fine sand, then very small stones, then larger pebbles.
Mix some soil and water together to make muddy water, then pour this through your filter. Collect the water that comes out in another container. Does it look any different? You could try changing the items in your filter - maybe you want to put a layer of cloth or blotting paper at the bottom to remove the finer dirt. If you are doing this with a group of people you could compare who has the best filter.
Although the water may look cleaner, remember that it may still be contaminated with bacteria and things that are too small to see, so do not drink it.