Choosing Your Aquarium

A wide variety of commercially available aquariums are designed specifically for marine organisms. The large number of styles, shapes, and sizes will fit just about everyone's taste. Designs include freestanding rectangular, spherical (fish-eye), and square tanks - as well as models that resemble a low coffee table.

Regardless of shape, the two basic materials used in construction are glass and acrylic. There are advantages and disadvantages to each type.

Size of Your Aquarium

Determining the proper size of the aquarium depends on the number and type of fish, the available space and economical constraints. To the new marine hobbyist the best advice is the larger the aquarium the better.

Marine aquariums must be larger than their freshwater counterparts. Whereas a 10-gallon tank can be perfectly suitable for freshwater fish or goldfish, the same size can cause major problems when maintaining marine fish. Many species of marine fish are very territorial and require large areas to coexist peacefully with other species. Secondly, smaller aquariums may foul rapidly, so once a problem occurs you have little time to correct the situation. Therefore, the larger the aquarium the better. As a general rule, start with a standard rectangular with a capacity of 20 to 40 gallons.

More Information on Tank Size

Tank Shape

You should give careful consideration to the shape of your aquarium. The various available shapes have a direct effect on the watery environment. Long tanks provide greater surface area and reduce depth. High tanks provide greater depth and reduced surface area. The greater the surface area of the tank, the better the gas exchange at the water surface - and therefore the more rapid the dissipation of carbon dioxide and the absorption of oxygen. Certain aquarium shapes can appear pleasing to the eye, but may not have the environmental advantages offered by more standard designs. For example, fish-eye tanks provide an ultramodern appearance, but are generally unsuitable because of an extreme reduction in surface area. The number of animals that can be maintained in such tanks is quite limited. In addition, maintenance of the fish-eye aquariums is often very difficult and time-consuming including the cleaning of the gravel, addition and removal of decorative items and fish, and simple cleaning of the inside surfaces.

As a general rule, if two aquariums of the same volume differ in the size of their surfaces, select the one that provides the greater surface area.

Aquarium Weight and Placement

A very important consideration in deciding the size of the aquarium is its total weight when in full operation. In determining where the aquarium is to be placed, you must consider the combined weight of the aquarium, water, decorations, coral rock, and so on.

An aquarium can be placed on a piece of furniture if it capable of supporting the weight. Keep in mind that saltwater eventually will get on the furniture. It is therefore recommended that you purchase a cabinet or stand specifically designed to support an aquarium. Numerous styles of wood or wood-grain finish cabinets are sold, often with storage space for air pumps, filters, and other equipment. Other cabinets or stand provide space for additional small aquariums.

You should also be certain that the floor in your home would support the weight of an aquarium. If you live on the upper floor of an apartment or condominium, check to determine what weight can be supported.


A fish tank will require a stand to keep it off the floor and put it at a height that allows easy viewing and access. Stands made out of iron or metal are not recommended for a saltwater aquarium, as they will quickly rust when they come into contact with salt water. A stand made of wood or acrylic will last much longer. Although it is possible to build your own stand, the stability of a tank stand is extremely important, so a task like that is best left to a master craftsman. A commercially-made stand that is sized to fit your aquarium is a great option.

Tank Location

Where the aquarium is placed is a matter of personal preference. It makes a beautiful focus in a living room, den, bedroom, or any other room. Larger aquariums can be placed as an attractive room divider. Wherever you decide to situate the aquarium, it is important to have easy access to multiple wall outlets to minimize the use of extension cords.