A hodge-podge of aquariums scattered around your house looks bad, and makes maintenance harder than necessary. An aquarium rack that holds several different aquariums is an excellent solution -- in addition to saving space, an aquarium rack can be very aesthetically pleasing and keep tools and supplies hidden.
Concepts of Construction
At its core, an aquarium rack is simply a system of shelves designed to hold several aquariums. You can construct a simple, utilitarian structure or, if you have the skill, you can construct furniture-quality racks that serve as a showpiece in your living room. Usually, hobbyists make aquarium racks by constructing a wooden 2-by-4 frame that holds several plywood floors, on which the aquariums rest. Others use threaded metal rods to support laminated particleboard floors. In addition to building a wood or metal rack from scratch, you can use heavy-duty, commercially produced shelving units as an aquarium rack.
If you have or expect to have children, consider adding a transparent door with locks to keep unauthorized hands away from the tanks. Additionally, consider the tools and supplies you use when maintaining the aquarium; if you wish, you could build drawers or other compartments to hold these items. Consider drilling holes through the levels to route electric cords and hoses through.
Location, Location, Location
Almost as important as the design of your rack is its placement within your home. You must consider the aesthetics of the chosen location as well as the maintenance and safety aspects when selecting the best spot for your aquarium rack. The ideal aesthetic spot for aquarium racks is the living room or den, where it can be a stunning focal point. However, you must consider the maintenance needs of the tank -- it is important that hoses will reach the aquarium for maintenance. Additionally, consider the ramifications of a broken tank or flood in the area where the aquarium rack sits -- putting an aquarium rack near computers, televisions or electronics is a bad idea -- an accident could end up costing you a fortune.
Remember that aquariums are heavy -- in addition to the glass, gravel, filter and fish, the water inside the aquariums weighs approximately 8 pounds per gallon. While a 10-gallon aquarium contains about 80 pounds of water, a 40-gallon aquarium contains over 300 pounds of water. This means that while you can probably build an aquarium rack for a few small tanks, constructing racks for large tanks is a job for professionals.