A saltwater fish tank resembles a mini ocean with marine life inside. It is very much similar to an aquarium (which is more popular), but then an aquarium houses tropical fishes like goldfish.

There are different compositions, styles, sizes and shapes of saltwater fish tank. The more commonly used tanks are discussed here.

Glass fish tanks are the most common and one of the cheapest. It is usually combined with silicone. The edges and corners are framed in plastic. However, this type of tank can be sometimes brittle. It is not as durable as the other kinds of tanks.

A glass tank sometimes acquires cracks with the changing weather conditions. The combination of heat and cold temperatures can cause glasses to become brittle and break later on. Also, glasses are prone to scratches, especially the low quality ones.

Acrylic fish tanks are stronger and lighter compared to glass tanks. The soluble cements combine with acrylic directly. Acrylic material is less prone to scratches compared to glass, and can therefore hold shelled organisms like shrimps and crabs.

However, acrylic tanks do not have full openings on top. This can be quite annoying for some tank owners, especially in the desire to clean out the tank once in a while. Instead, there are several portholes only to let the tank "breathe."

Laminated glass tank is a combination of glass and acrylic. Lamination makes the tank sturdier and more resistant to the heavy weight of water. It therefore the better choice compared to glass or acrylic, budget permitting. Also, in case of breakage, the glass or acrylic underneath provides extra support to keep the damage in check.

Fiberglass tank is either reinforced plastic or reinforced concrete. The plastic type is used for bigger tanks although it is not transparent. The concrete type is used for more heavy duty tanks. It has to be waterproof to prevent leaking and sudden break down of water.

A kreisel fish tank is a rounded aquarium created to accommodate dangerous water animals like jellyfish. This fish tank gives a slow, circular motion of water that keeps fishes suspended. It also does not have sharp edges to avoid trapping fishes.

A rounded fish tank has a circular and underwater lid. Pseudokreisels have a curled surface at the bottom and a straight surface on top. This is the same with either a U or a semicircle shape.

A hexagonal fish tank is suitable to place in a corner of your room. Other fish tanks are cuboid, L-shaped and bow-front. These irregular shapes are made to fit different types of rooms.

There are also tanks made of polycarbonate. Although this is not the best material to use, with a strict budget, polycarbonates are fine. It will just be more prone to scratches. And the edges and corners are harder to bind and seal together.

Tanks also have different sizes and volumes. A small size can hold 1 to 10 liters of water. Bigger tanks are more feasible because of their resistance to fast fluctuations of PH and temperature. It is more stable and easier to maintain.

A reef fish tank has a 100 liters capacity.