Water Filter

Materials:

• Plastic cup

• 2L empty soda bottle

• Coffee filter

• Sand

• Pebbles

• Gravel

• Water

Instructions:

1. Fill bottle with dirty water.

2. Put the coffee filter in the plastic cup about 1/3 of the way down and tape it down for security

3. Layer the sand, pebbles and gravel in the coffee filter in any order (pick an order that you think will dilute the water the best)

4. Pour the water into the cup with your coffee filter and see how clear you can get the water to filter out to

5. Repeat steps 1 – 3 until you get a really good filter (you may want a few cups and a few coffee filters)

6. Challenge: try using different materials to create the best filter.

7. Note: if you write down your observations after each trial, it will help you determine what changes you need to make to create a dynamite filter!