The minimum requirments for one of these sharks is a 180 gallon. All the experts say this as well including Scott Michael. I recommend buying his book. "Aquarium Sharks and Rays".
One thing to get straight right off the bat is that they are "NOT" cat sharks. They are no relation what so ever. The bamboo shark comes in a few different forms including the banded, spotted, and gray. They are related to the whale shark and nurse shark.
I have two banded bamboo sharks that I hatched in my 180 acrylic tank. They are now about 10" long. Once they reach the 2 foot mark I will be upgrading to a 300 gallon even though the 180 would be perfectly fine.
They are very tough and should only be bought if you allready have the 180 gallon!
You should purchase the eggs and not sharks that are allready hatched since they will be more comfortable with you that way.
In captivity they rarley reach 4ft long. If you have a tank that is too open they will fell less secure and stress can cause harm to the animal. In the wild they live around coral rubble and stay on the bottom around the caves and rocks of the reef. They are well adapted to live around tight spaces and are very flexible. They are deffinatley suited for aquarium life with a little rock work in the center, (Cave preferably).