We used resources easily found around us to make water filters and tested them with water from a nearby marsh. It was a friendly competition about who could build the best filter. That means the dirty water poured in the top should come out clean at the bottom. The best team used a lot of sand which we think caught the dirty pieces. We also used paper towel and gravel. It was interesting to learn that if we were in a desperate situation we would be able to use natural resources to survive. For some people around the world this is normal and we appreciate a lot more now that we can just turn on the tap and get fresh drinkable water.