Fun Water Experiment to Cool off in the Heat!

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Recently my boys and I used the engineering design process to design our own sprinkler system. After my son created a design we knew we could make, we designed to experiment with water flow and create a water experiment.

A fun way to explore how water flows in a pipe with holes. And a great way to cool off!

Exploring How Water Flows through holes in a Pipe

In one of my engineering jobs, we used pipes to distribute liquids and gases in our chemical process. To evenly distribute the liquid or gas into a certain area, we would drill holes into a pipe. If we wanted for the spray to be forceful, we would drill a few holes, and for less intensity we would drill more holes.

I thought our new sprinkler would be a great opportunity for my boys to experiment with the concept of more holes equals less flow per hole.

As a reminder, below was the final design for our sprinkler system.

Building our Sprinkler

While I supervised, the boys started constructing their sprinkler. The little one helped measure, while the older two used a hand saw to cut each piece.

The boys working together to build the sprinkler.
Learning to safely use a hand saw!

Once all the pieces were cut, the older two assembled our sprinkler using the tees and elbows. In all they used 3 tees, 8 elbows, and 1 four-way connector. We also used a FNPT to PVC connector to connect the sprinkler to our hose.

The final result!

First Water Flow Experiment: 3 Holes

Now it was time to do our water flow experiment! We started by removing the top piece that connected the two rectangles. Next we drilled 3 evenly space 1/4″ holes into the removed piece.

Our first water experiment. How does water flow through a pipe with 3 holes.

The boys reconnected the piece to the sprinkler, and turned on the water.

Water flowing out of 3 holes.

Then it was time for some fun! The boys started playing in their sprinkler, running back and forth, back and forth, so proud of what they had made together. And then there was the time they just sat under the water.

The boys playing in their sprinkler!

Second Water Flow Experiment: 5 Holes

After the boys had played for awhile, we removed the connection piece again, and drilled two more holes in the pipe. Now we had five 1/4″ holes in our PVC pipe.

Our second water experiment. How does water flow through a pipe with 5 holes.

My oldest put the drilled PVC back in place, and turned on the water.

Water flowing out of a 5 hole pipe.

Immediately we all noticed there was less water coming out of each hole. But it was still fun to play in!

Third Water Flow Experiment: 11 Holes

We removed the connection piece one more time. This time we drilled six more holes in the pipe. Now we had eleven 1/4″ holes in our PVC pipe.

Our third water experiment. How does water flow through a pipe with 11 holes.

My oldest put the drilled PVC back in place, and turned on the water.

Water flow out of 11 holes!

Wow! Now we could really see a difference! My son yelled “There’s barely any water coming out!”

And I said “Yes there is! The same total amount of water is coming out of the holes. Only, a lot less water is coming out of each hole because its spread out evenly through all eleven holes!”

Then he said, “Well I like our sprinkler with less holes, then!”.

The boys played in the sprinkler until the grass had turned to mud, and it was time to go in. Reflecting later that day, I realized that the boys had learned so much today!

  1. My 3 year old learned how to use a measuring tape.
  2. My 5 and 9 year old learned how to teach a 3 year old (that was fun to watch!).
  3. They learned how to use and safely handle a hand saw and drill.
  4. They learned how to work as a team.
  5. They learned how to put together PVC pipe.
  6. They learned that the number of holes in a pipe affects how much fluid flows out of each hole.

I love how the water experiment not only taught them fluid dynamics (an upper level class I took in college), but also practical life skills. Plus it kept them busy for an entire day! A necessity during the long days of summer.

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Interested in learning more about how water works? Here are some more fun water experiments we’ve done:

Make a Rainbow using the Properties of Water
Make an American Flag Using Water Science Experiments
Appearing Snowflake: A Winter Activity for Kids

Or try one of these STEM Activities with water:

How to Make it Rain Science Activities for Kids
DIY Water Wall for Summer STEM Fun!