There are several different kinds of aquarium stands, ranging from simple black metal rod constructions to quite fancy 12 wood-grain or faux wood-grain foundations with matching hoods. These latter stands normally have a cabinet below for storage of accessories like nets, siphon tubes, food, spare parts, and the like. There are typically no initial problems with good quality commercially built stands, and they're built to fit exactly the commercially assembled aquaria. Stands used to support marine tanks should be checked often for rust as the corrosive action of salt water is many times worse than that of fresh water. And regardless of how careful you are, there are always some times when water is spilled or a few drops run down the sides of the tank and touch the stand. Even the air in the immediate vicinity of the tank is more saturated with salt and can have an effect on the metal stands.
Strength is likewise important in aquarium stands. The commercial stands are made to take the stresses of the normal fish tanks and would support the weight of the water, coral, etc., with no trouble. For those who prefer to build their own supports for their tanks, keep in mind that salt water is heavy (about 8 1/2 pounds per gallon) and a 50-gallon tank thus bears water weighing about 425 pounds. Add to this the weight of the gravel, coral decorations, and tank itself and you have an idea of what weight the stand needs to support. When considering the larger tanks of 125 gallons or so, you're talking of over 1,000 pounds of water alone. That's more than half a ton! Begin adding the weight of the gravel, decorations, etc., and you not only have to take into account the strength of the stand but also of the floor the tank would be standing on. For these larger tanks it is wise to consult someone well versed in construction, or better yet structural engineering, for advice on whether your floor could support the weight.
Materials used for aquarium stands vary depending upon the size of the tank and the esthetic requirements of the aquarist. Other aquarists are contented with a commercial black metal stand, others the fancier wood-grained models, and still others use cement blocks combined with heavy wooden boards. The cement block stands can be left as it is or covered on the front and sides using a cloth or even wood paneling. For those on an unlimited budget specially built bases such as those used for room dividers or merged into part of the wall can be considered. The crucial factor is strength, beauty having to be a secondary consideration.