Walking Water (Grades K-5)

Build your own rainbow right at home in this beautiful hands-on activity.

3 glasses with colored water

Did you ever imagine that water can walk? In this experiment, you’ll be able to see just how, while building your very own rainbow in the process. 

What You Need

  • 7 small plastic cups or glasses 
  • Paper towels
  • Red, blue and yellow food coloring
  • Water

What To Do

  1. Line up your cups in a row. Fill each cup with water, leaving about an inch of space at the top. 
  2. Place several drops of food coloring in your cups as follows: 
    • First and last cups: Red
    • Third cup: yellow
    • Fifth cup: blue
  3. The remaining cups should not have any food coloring in them. 
  4. Connect the cups in sequence using paper towels. Take a moment to draw a diagram of this setup and color it in to show what you predict will happen. What will the liquid look like in the second, fourth and sixth cups? 

    diagram of cups

  5. Take a half-sheet of paper towels and fold it in half lengthwise twice. If you need to, trim the ends of the folded paper towel so that it won’t stick up too high when it is placed in between two of your cups. 
  6. Connect your cups with the paper towels so that one end is in one cup and the other end is in the next cup. Each cup should have two paper towels touching it, except the ones on the very end. 
  7. Sit back and watch the water “walk” across your rainbow!
  8. Check your diagram. Did you correctly predict what would happen? 

Close up of experiment

You can try this experiment again with different colors, or a different sequence of colors. Or space the cups out — how far can the colored water “walk”? 

Share what you found with us by tagging #CapRegSummer or emailing summeradventure@neric.org.