This is a really helpful article about setting up a small fish tank. She knows about caring for fish, and setting up an attractive aquarium. Spent 20 minutes looking through my internet history to find again. Pinning, so I don't lose it!
This is the world's smallest working aquarium, which holds just two tea spoons of water and measures just 30 mm. wide by 24 mm. high and 14 mm. deep, can be held in the palm of your hand. It is so small there is only room for these baby zebra fish.