The Right Size Tank

First – Get the Right Size Tank

Marine aquariums come in a wide variety of shapes and sizes, from 5 gallon desktop versions to mammoth 300 gallon or larger tanks that easily occupy a wall in your house. Most tanks are the standard rectangular shape, but you can buy bowls, cylinders, hexagons, and bowfronts, among others. As you would expect, prices increase along with the size of the tank, and larger tanks require matching peripheral equipment (pumps, filtration, lighting, protein skimmers, etc.).


Although smaller tanks are less costly than their larger counterparts, medium-sized and larger aquariums turn out to be easier to keep successfully. Maintaining a healthy marine environment is trickier than in a freshwater tank. A larger aquarium will be more resistant to equipment malfunctions and water quality problems, The extra volume in a larger tank is a buffer against temperature swings and the build up of toxic by-products which can sicken or kill your fish. We recommend aquariums of at least 30 gallons for most first-time marine tank owners.


Space and time are also important in choosing the right size tank. Consider the space you have available not only for the aquarium but for its support and peripheral equipment. Once you add up the glass, water, substrate, rocks and the rest of the necessary equipment, an average aquarium will weigh approximately ten pounds per gallon. A full 30-gallon aquarium will weigh around 300 pounds and require a sturdy stand. Rectangular tanks in the 30 – 55 gallon range are usually between 36 and 48 inches long and 12 to 18 inches deep. Tanks will need some sort of filtration system, typically attached at the rear of the aquarium, which adds several additional inches of depth.


Thanks to Michael Griffith of Segrest Farms for contributions to this information.