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Water Filter

Explore the process of water filtration. How do water filters work? Try this experiment and build a water filter out of simple materials to get rid of big and small things that float in the water.

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  • Where will you share this adventure?
  • What does a water filter do? Why would you need to use a water filter?
  • What materials could you use to build a water filter?


  • Use an old re-usable paint tray and create a model to learn how a real water filter works.
  • You can even try creating a small simulation to test natural water filtration with a model coastal shoreline.
  • Watch your water become cleaner as it moves through your filter.


  • How did you make your filter? Why did you use that design?
  • Do you think your homemade filter would work? Why shouldn’t you drink the water from your homemade water filter?
  • What did you like about this adventure? How would you do this adventure differently?
  • Remember to submit your activities on our Scouts for Sustainability Take Action Map

Keep it Simple

  • Make a water filter using the end of a plastic water bottle and natural resources that you find outside! How effective is your water filter? What does it clean out? What do you think it misses? Why not also take a look at water flow in general? Try making your own dam to see how larger amounts of water flow and changes in levels.

Take it Further

  • This water filter experiment only takes larger objects (that we can see with our eyes) out of the water. What will it take to make the water drinkable? How can you test it? What are some smaller objects in the water that could be dangerous to humans? Could you use technology to help you, such as a microbit? Take it further by learning about watersheds and nature’s natural water flow system that makes up much of our rivers and more! How does this water compare in cleanliness to your filter?