Make Your Own Water Filter

Practice using the engineering design process to design, build and test a water filter.


Age of children

  • Can be adapted for elementary through high school ages


Materials to build with

  • 2 liter plastic soda bottles
  • Gravel
  • Sand
  • Sponges
  • Paper coffee filters
  • Paper clips
  • Straws
  • Cotton balls
  • Rubber bands
  • Tape (electrical or duct)
  • Panty hose
  • Clay or putty
  • Cotton batting
  • Cheesecloth, mesh, or some other fabric with large porous holes
  • Scissors

To make the dirty water:

  • A large clear bucket filled with water
  • Food coloring or soy sauce (to represent chemicals)
  • Raisins or dried beans (to represent animal/human waste)
  • Potting soil (to represent the earth)
  • Cooking oil (to represent motor oil)
  • Torn pieces of paper & Styrofoam (to represent litter)


  • 1 hour, 30 minutes

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