The Virtual Aquarium will let you build your own fish tank, and add fish and other decorations. The items you can add are displayed around the outside; just drag them into the tank.
Build the background first, add bottom pieces across the whole bottom of the tank; then add extras. Place the fish last. Move the bubblers too. Then you can draw and paint your aquarium!

First download and print an empty tank for the artwork.
Have fun!

Enter the Aquarium | Art Lessons