Participants were given a class of "dirty" water. If I remember correctly the water was made "dirty" by mixing it with a chocolate mix of some kind. The goal was to create a filter out of available materials, such as porous rocks and sand. Below is the filter my 9 year old created.
As you an see, the brown water is definitely a dirty water that does not look drinkable. The "dirty" water was poured into a cup filled with porous rocks and sand and is slowly filtering into the cup below. Below is the result of the filter my 5 year old created.
Not too bad! The water is slowly filtering into the cup below. The filtered water isn't quite clear and is certainly not considered drinkable, but this very simple water filter is doing a relatively good job of filtering out a large percentage of particles!
We didn't have a lot of time to improve our filter, so this summer I have plans of doing this again with my girls, using materials we have around the house. Should be a fun time!