Materials:
A see-through glass jar
Plastercine

What to do:
1. Make small, flat fish shapes with eyes out of the plastercine.
2. Make bubbles, plants, and/or reefs to add to the scene to make it look more realistic.
3. Press your shapes onto the side of the jar however you want. Be creative.
4. Here comes the hard part. Take small pieces of blue plastercine and carefully press it onto the sides of the jar. If you run out of blue, take some off and mix it with green. Then put it back on.

Alternatives:
You don't have to make a fishtank. You could make anything you want. Here are some examples:
a forest scene,
a park scene,
or shapes with a backround.
Be as creative as you want but remember, be careful when you're making backrounds. Plastercine can easily come apart!