I know I build things for fish to live in, but why is it called an aquarium?
I  have a big Aquarium in my back yard , is a vivarium of any size having at least one transparent side in which aquatic plants or animals are kept
oh cool!  What kind of fish can go in them?
As a Fishkeepers use aquaria to keep fish, invertebrates, amphibians, aquatic reptiles such as turtles
Can I just put water in there?  Or is there anything else I need to do?
Well,its simply .is a water-filled tank in which fish swim about
How long have people had aquariums for?
The Aquarium: An Unveiling of the Wonders of the Deep Sea" in 1854.