An aquarium is a place for keeping water life. In the past, people would keep goldfish in a bowl. However, most people now think this is cruel.

An aquarium should be a place where wild life can live as naturally as possible. Some wildlife need to hide in plants; some like to lie on the bottom, while others live near the top.

Because aquaria are still water, there is not much chance for oxygen to get into the water unless some kind of aerator (bubbler) is used. Fish poo also builds up in the tank unless the bottom is cleaned regularly.

Some kinds of fish do not get on with others, while if too many fish are kept, they can all begin to fight.

Keeping an aquarium needs more knowledge and greater care than you might at first think.