There are few activities that humans undertake that cut across as many areas as aquarium keeping. Think, for just a second, about all of the different categories that aquarium keeping can fit under:
It's a hobby: The more you get into keeping an aquarium, the more curious you are about the next level in aquarium living. Almost anyone who starts out with a miniature bowl set eventually gets curious about what other types of species they could keep in their homes, the type of sets they could own, and so on. What's more, there is always more to learn: what kind of environment fits with which kind of fish, different levels of minerals in water, species of fish, and so on.
Companionship: Now, fans of furry creatures might take a bit of a skeptical approach to the idea of fish as good pets, but the fact is that fish can give as much satisfaction as any other pet. It is cathartic to watch them swim around in the tank, notice the way that they move and the different ways in which they interact. You won't be able to take your fish out and pet them, but you can still talk to them and it is always nice to have responsibility for a life apart from your own.
Home decor: One of the really great things about keeping an aquarium is that it adds a bit of decoration to your home, kind of like a living mural. Just go over to the local pet store and spend a little bit of time near the fish tanks; it is hard to resist the beauty of an aquarium full of fish, and that beauty is apparent both in the living species in the tank and in the decorations you put in the aquarium.
Before we move on, it is important to note that there are species of animals, aside from fish, that you can also keep in an aquarium. We are not just talking about lizards here, although the aquarium structure will work as a home environment for reptiles, but other aquatic animals that will be right at home alongside your fish. Salamanders, frogs, turtles, snails (the exotic kind) several different species of crustaceans, and so on fit the bill for an aquarium, as well as any kind of fish.
Some Aquarium Tips
Keeping an aquarium does come with a fair measure of responsibility and dedication. It is best not to plunge right in with a 40 gallon saltwater tank. Instead, start out small. You don't want to start dealing with activated carbon (find a description here) and filters until you understand how they work. There are plenty of species of fish (goldfish, Siamese fighting fish, tetras, and more) that you can keep in a simple bowl and learn the tricks of proper feeding and environment. Best of all, these are hardy species that don't tend to go belly up when you do something a little bit wrong (ironically, the fussier the fish the more costly, so in order to protect that $60 beauty you will want to make sure you go in with some knowledge).
So start out small.
The next tip is, make sure you get good advice when you do decide to upgrade. Again, the rule is fairly simple: the more beautiful the fish arrangement, the more costly and the more finicky you have to be about tank conditions. There are literally hundreds of different types of equipment and cleaning tools you can buy, and you will want to know which ones are right for you.
As we mentioned in the first little bit, many people keep aquariums for their decor factor. The more fish you have in a tank, the lovelier that living mural becomes. However, keep in mind that some types of fish just will not get on well together. You will have to know the relative aggression level of species within the same tank, and just where in the tank they are likely to spend most of their time and feed.
I think that any fish lover dreams of owning a huge, wall-sized aquarium that is a little reminder of the reefs off of Hawaii or Australia. You have to work yourself up to that point, however. With commitment, and armed with knowledge, you can make that dream come true.