To truly understand the diversity of aquatic environments, many hobbyists have begun keeping "biotope" or "geographic" aquariums. In these tanks, the hobbyist attempts to simulate a specific habitat. The fish, plants, gravel, decor, and even water are each important parts of these set-ups. Generally speaking, a "geographic" aquarium simply represents an environment, and the items added should appear natural and conform with that habitat. In a "biotope" aquarium, more care is given to be certain that not only does each item
appear appropriate, but that it actually
is authentic to that region. For instance, the wood that is used should be of a type that is native to that area, and the sand must be the correct type of mineral for that region. The same is true for the plants and fish, etc. Setting up a true biotope aquarium can be an extensive undertaking. A geographic aquarium is a bit easier, and still allows an understanding of the habitat. Both require knowledge of the water conditions, which the aquarist should attempt to simulate in these nature environments.