Walking Water Science Experiment for Kids

Learn about capillary action with this Walking Water Science Experiment for kids. It’s so easy to set up and you probably have all of the simple supplies you need already in your kitchen. With a bit of science, you’ll get to see the water move and mix colors all by itself. It’s mesmerizing to watch and your kids will have so much fun learning at the same time.

If you want to make your Color themed lessons a breeze, then check out the Color Activity Pack. It’s filled with math and literacy centers, fine motor activities and arts and crafts templates. All of which are aligned with preschool learning standards. Check it out today.

Disclosure: Adult supervision is required for all activities at all times. Some of the links provided in this blog are affiliate links. I will be paid a commission if you use this link to make a purchase.

More Color Crafts and Activities to try

Kids of all ages will have a great time learning about color theory with some of these color themed play ideas.

1. Color Wheel Art for Kids (Free Printable Template)
2. Color Match and Clip Cards (Free Printable)
3. Paper Plate Color Match Activity
4. Rainbow Paper Experiment
5. Why Do Leaves Change Color – Science activity for Kids

For more ideas, take a look at these 25 Colors Crafts and Activities for Kids.

Materials Needed

1. 6 containers – Mason Jars are great for this activity
2. Food coloring
3. Paper towels
4. Water

How to Make a Walking Water Experiment

Set up your containers

1. Set up all of your containers in a circle.

You can use any type of empty cup or empty jar for this easy science experiment. As long as they are grouped close enough together so that your absorbent paper towels can have one end in each of the empty glasses, this simple experiment will work.

I would also recommend using clear cups. While this doesn’t have an effect on the way the walking water activity works, it does make it easier for kids to see how the water is moving, without needing to touch and move the cups themselves.

2. Place water into every alternate container (1st, 3rd and 5th cup).

About two thirds to full should be fine, there’s no set amount of water you have to use, just make certain that the water level is high enough so that your paper towel can reach down and soak it up.

Do not pour water into every container or else the experiment won’t work properly.

Add in the food coloring

3. In the containers with water in them, add a few drops of food coloring. Start with the primary colors, yellow in one, red in one and blue in the last container.

How much food coloring you use is up to you. I find that using only 5 – 10 drops of each color is enough for this experiment to work. (ie. they colored water will move and mix in the empty jars.) But it doesn’t stain the paper towel fibers enough for young children to see clearly. If you use more food coloring, you will be able to see a very strong band of colored water walk up the towels and into the next jar.

You’ll notice that in the photos below, although the paper towels have a slightly colored tinge, it’s not a very obvious color change. If you’re doing this experiment with toddlers or preschoolers, I would recommend using more food coloring than I did. That way they get to really see the process of what’s happening and not just the end result.

Add in the paper towels

4. Lastly, you’re going to fold up a square of paper towel and hang it in between the tiny gaps of the two of the containers.

You want one end of the paper towel to reach inside the container with food coloring in, and the other side to sit in the empty container. It doesn’t matter which type of paper towel you choose to use, because they are all designed with small fibers that are perfect for soaking up a little bit of spilled water.

5. Repeat step 4 for all of the containers. You’re going to need a strip of paper towel to hang between two of each of the jars (six in total).

If the opening of your jars is a more narrow space, consider adjusting the size of your paper towel strip. I ended up cutting my squares in half, and then folding them into thirds. This made them more narrow and easier to fit in between the two jar openings.

Watch and wait

6. Now all you have to do is wait and watch as the colored water travels up the paper towel and pools into the empty container.

As two colors from different containers drain into the same one, you’ll see the different colors of water mix, creating the secondary colors of orange, green and purple. Viola, you’ve just made your own rainbow. My favorite part of this step is when the water is initially moving, the two colors stay separate for a time. So in one jar you can see a pool and blue, a pool of yellow and a small section of water where they’ve mixed and turned green.

This final step of the walking rainbow experiment can take a long time. Although you can start to see results after about 30 minutes, the whole process can take several hours. That is one reason why this fun experiment is also a great way to teach your children patience.

What You’re Learning

Capillary Action

The Walking Water science activity is all about the process of capillary action.

Capillary action is the movement of a liquid through or along another material against an opposing force, such as gravity – Study.com

In this case, you can see the water climb up the fibers of the paper towel (which act like capillary tubes) and down again into the empty jar. This movement of water is easy to see because we’ve used food dye molecules to make the water colored and easier to track.

Another experiment that explores capillary action is the Color Changing Flowers Experiment. Where you can use capillary action to create a blue (or any color you wish) rose.

Color Mixing

If you are doing this activity with toddlers or preschoolers, then you can focus on the color mixing part of the activity. After starting out with the three primary colors of blue, yellow and red, you’ve ended up with a whole rainbow. This is the perfect time to discuss the different colors they see and practice some basic color recognition.

Planning and Organization

This walking rainbow science experiment has several steps that need to be done in a specific order for this activity to work. For example, you need to add the food coloring into the glasses of water before the paper towels. If you don’t, then the clear water, instead of coloured water, will go between containers and the colors won’t mix and create new colors.

Organizing the required materials beforehand, as well as planning out each step before you do it, is a great way for kids to strengthen their executive functioning skills.

Scientific Method

This rainbow water experiment can also be used to teach older kids about the scientific method. Explain what you’re going to try, but ask them to make and write down a prediction before you perform the activity. Once the experiment is complete, ask them to write down the results and why they think the water traveled the way it did. This is a fun way to encourage your budding scientist to engage in critical thinking.

Are you going to try this Walking Water Science Experiment with your kids?
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