Fish Tanks can differ by size, material and style. Usually fish tank is made with glass in size from small tabletop decorative item to huge cabinet installations in office, hotel or mall. They also categorized by freshwater or saltwater and by the specific environment they replicate (e.g., cold water for goldfish, tropical for warmer-climate fish, coral reef etc.). Plastic tanks are for breeding, dividing different species from others, like as Betta fish, or just for convenient transporting.