What do we mean by a deep reef fish community? Although 'deep' is an arbitrary term, in this article we will refer to those fishes that live on or adjacent to corals reefs, at depths in excess of 100 feet as deep reef fishes. More... (http://www.advancedaquarist.com/2005/8/fish)

good reading

Honey, I want to keep those deep water fish. I'll need a new tank, one that's 100' deep!

a lot of deep water fish are availble, unfortunately, most will die shortly.

Unfortunately, that is what happens when people don't take the time to research what they are adding to their tank.