Materials Required:
Two empty water bottles
Clay
Tubing (12-16 inches, 2 pieces)
Coffee filters (6-7 per bottle)
Cotton balls
Large piece of cardboard
Packing tape
Food coloring
Beaker or plastic container
Steps Involved:
Cut the bottoms off the empty water bottles and remove the caps. Seal the openings with clay, creating small holes for the tubing.
Insert one end of each piece of tubing through the clay hole in the respective water bottles. Ensure the tubing is secure and reaches as far down as possible. Check for leaks; water should only travel through the tubing.
Place approximately 6-7 coffee filters and a few cotton balls inside each water bottle.
Use packing tape to attach the water bottles to a large piece of cardboard, leaving about 5 inches between each bottle for the funnel and container underneath.
Position the ends of the tubing into a funnel to determine where to secure it on the cardboard. Tape the funnel in place and ensure the model is securely mounted to a wall or countertop.
Place a beaker or plastic container underneath the funnel to catch the filtered liquid.
Reuse the bottoms of the water bottles to mix food coloring with water. Students can gently pour this “waste” into the model and observe the filtration process.
After each demonstration, replace the coffee filters and cotton balls to prevent saturation. Be prepared to fix any leaks with extra clay or sealant if necessary.
English 
Portuguese