CHOOSING THE SYSTEM
Fish keeping is usually divided into two categories: freshwater and marine. We will also deal with brackish water aquariums, for which many fascinating species of fish and invertebrate are available.
Among the first things that you will have to decide is which of these aquariums you wish to set up, and whether you intend to keep a tropical or a temperate aquarium. Tropical tanks dominate the aquarium hobby, because of the spectacular species of fish that can be kept in them.
CHOOSING THE RIGHT TANK
As a general rule, the larger the tank you choose, the more stable the water chemistry will be once the aquarium is functioning. You can use any shape of aquarium that you like, but make sure that the glass is clear and free from distortion. The most popular aquariums are all-glass tanks bonded by silicone sealant, although numerous other models are available, such as one-piece plastic tanks, or the older less common, metal-framed tanks. The latter are not recommended for marine environments, as the frame may rust