earth day science experiment

Pollution in a Fish Tank: An Earth Day Science Experiment

Earth Day gives children a chance not only to learn about keeping our world clean, but also to appreciate the ways in which God designed our world.  This science experiment using a fish bowl will give kids an up-close look at how pollution takes hold and also to understand what God says about preserving our planet.


– Empty fish tank. If not available, a large pot or bowl will work.

– Water

– Blue liquid food coloring

– Freshly cut leaves from any outdoor plant, tree or bush

– Vegetable oil

– Feathers (can be purchased in most craft stores – or plucked from a feather pillow)


Today, in celebration of Earth Day, we’re going to do a little experiment that will show us things about our planet. Earth Day has been celebrated for 43 years, teaching kids and adults how to take better care of our planet. Using this terrarium, we’ll see what happens when there is an oil spill.


1. Fill fish bowl 2/3 full with water.

2. Add blue liquid food coloring to create an “ocean” environment.

3. Pour a few tablespoons of vegetable oil into the water.

4. Drop in the cut leaves and feathers.

5. Stir constantly and note what happens to the water, feathers and plant life placed in the water.


Oil and water don’t mix. So when there is an oil spill, the oil will rise to the top of the water. It then washes ashore where the damage to fish and water foul is disastrous. When oil gets on the feathers of waterfowl, (such as ducks and seagulls) the feathers become covered with goo and stick together. When that happens, feathers lose their buoyancy and the birds cannot stay afloat, let alone fly.

Questions to Ask the Children:

– Does the oil disintegrate after a certain amount of time?

– How does it change the way the plants feel in your hands when removed from the water?

– Are they slimy? Are they drooping?

– How do the children’s hands feel after putting them in contaminated water?

– What does they think will happen to plants, birds and fish when thousands of gallons of oil spill into the ocean?


When God created the earth it was clean, beautiful and unspoiled. Today we know that many parts of the world have been terribly polluted by smoke, factory discharges, oil spills and other disasters.

Fortunately, celebrations like Earth Day are making people more conscious of things they can do in their own homes and lives to prevent pollution.

How many of you recycle? What are some of the things that you have to sort out of your regular trash that need to be destroyed separately?  Mostly plastic.

Which of the things you recycle can be used over again?  Glass and paper.

Earth Day has also helped legislation be passed so that industries have to be very careful with their products, and their waste doesn’t pollute. As well, when there is a big oil spill, the media jumps in and reports every night on the damage being done so that people are aware. Today, industries are much more cautious than they used to be, but more work still needs to be done.

When our house gets dirty, what do parents do? They clean it up. Do they make you help? Hopefully – yes! We have to look at our world as the home God gave us. He wants us to keep it clean, the same as parents want us to keep our rooms clean.

Looking for more great science experiment ideas?  Then be sure to check out our Bible Science area!  And don’t forget to Become a Fan on Facebook, Follow Us on Twitter and Come Hangout with Us on Google+!


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