Each group needs:

• 6-inch square pieces of each of the following:

1. plastic window screening
2. hardware cloth (½" mesh)
3. hardware cloth (¼" mesh)
4. hardware cloth (1/8" mesh)
5. poultry netting (1" holes)

• 1-2 sheets of newspaper (to cover desk)
• 2 measuring cups or bowls (about 4 cups each)
• large funnel (large enough to have large pebble flow through the neck)
• ½ cup sand
• ½ cup small pebbles in various sizes from 1/8" to >1"
• ½ cup water
• Filtering System Journal, 4 copies
• Filtering Worksheet, 4 copies

To bind the screens for safety:

• duct tape

Optional materials:

• (optional) round coffee filter
• (optional) 2 tbsp. flour (only needed if using a coffee filter)