Just love to watch the baby fish (the white tadpole-like thing) being cared for by their parents. The protective parents would drive away other fish in the aquarium to prevent the babies from being eaten by adult fish.
This is the same aquarium that my son set-up two months ago. He changed most of the features, removed the artificial plants and replaced them with live plants. What he did is called aquascaping.
According to wikipedia, aquascaping is the craft of arranging aquatic plants, as well as rocks, stones, cavework, or driftwood, in an aesthetically pleasing manner within an aquarium—in effect, gardening under water.