1. How big is the space you intend on placing it, have the measurements with you.
2. Know your budget
3. Do you want salt or fresh
With this info. you can look for your aquarium, it seems like a sales ploy but the truth is the biggest thing you have room for or can afford the better.
Aquariums are a hobby where you almost always wish you had bigger, later. You will also see many fish you want long after you run out of room. Oh and speaking of room, given the choice between tall or long, go long. The surface area of the tank is important for a couple reasons, such as gas exchange and biological area in the gravel bed. Confused? if so leave a post and we'll talk more.
One of the biggest misconceptions I hear regular is, " we want to start small to see if its to hard for us to keep". WRONG, the smaller the enviroment, the harder it is to keep stable, and that is one of the most important rules of fish keeping. Keep the enviroment stable, ie. temp., ph etc.
I have always felt sorry for most people shopping for fish, that fail to encounter me.

Many, many folks encounter the less than knowledgeable, sale person or store owner, who's main purpose is to sell as much as possible. Or better yet, their whole knowledge base is what they read off the bottles or the sales rep. tells them.
Well if you can find a store thats been around awhile, the fish look good, and they make some sense when they talk, you may have gotten lucky.
But hey, now you have this site to help you on your journey to happy fish keeping. And I'm sure the fish will appreciate it
