Each group needs:

• 0.5 liter (500 ml) plastic water or soda bottle
• ½ cup granulated activated carbon (GAC); available from chemical supply stores and pet supply stores in the aquarium section
• 2-3 cotton balls
• jar, smaller in diameter than the 500 ml bottle so that the water bottle can be supported in the jar without falling through

For entire class to share (and the teacher to use):

• drill with small diameter bit
• kitchen knife or scissors
• 3 teaspoons of chocolate powder mix, such as Hershey's® or Nestle Quik®
• water, enough water for each bottle to be filled up 3-4 oz.
• pitcher or bucket, for mixing powdered chocolate and water
• 4-5 cups of sand
• 50+ marbles