When preparing for your new aquarium, you need to not only determine what size tank you want but how big of a space in your home you have to place it. You might like the 200-gallon reef tank that they have in the local fish store, but if you don’t have the space (and probably the experience to maintain it), and then you should keep on looking.
Typically, you’ll want to get the most prominent tank that you can afford and keep in your home. Contrary to belief, having a larger tank is easier to maintain than a smaller container for two reasons. First, fish need lots of room to swim and lots of oxygen in the water to breath. The larger the water surface in the tank, then the more considerable the amount of oxygen can enter the tank. Second, the hardware to maintain a more substantial tank has a bit more power to clean and maintain the water quality. The small tanks typically come with very cheap filters and water pumps. The larger tanks require more advanced and heavy-duty tools to work. Their filtration methods generally are much more sophisticated, and hence, do a much better job of keeping the water quality suitable for the fish.
Another critical factor in determining which size tank you’d like is to estimate the number of fish and other sea-life you’d like to keep in your tank. You’ll want to calculate the surface area of the tank to determine the number of fish you can store in that tank. Let’s say you’re interested in a standard-size 55-gallon rectangular tank. These sizes are typically about 14″ wide and about 48″ long. So that’s 672 square inches (14″ wide x 48″ long). A rule of thumb is 1″ of a freshwater/cold water per 30 square inches. So let say you have ten adult swordtail fish, which are usually about 2″ long. So that’s 20 inches of fish (10 fish x 2″ long). So take that 20″ of fish x 30″ square inches that they each require = 600 squire inches. So you have enough and then some. Sounds a bit complicated, but believe me, if you overcrowd your tank, you’re headed for disastrous results.
As you can see, having a more extended, rectangular tank (which provides lots of surface area) is much better than some of those taller tanks with less surface area. So don’t just shop for a tank based on the gallons it can hold. The amount of surface area is significant, as well.