^ agree with others.
What your thinking about is a sorority. You need at least 10 gallons, and should have between 4 and 7, maybe 8, females in the tank. It's preferable to get 4-6 because then you'll be less likely to overstock your tank. Some people say that 4 is too few (most say it's okay though)
You need LOTS of hiding places and a cycled tank. In a 10 gallon you can't put in any tank mates, you'll need at least 20 gallons to add other fish in as well. You'll also need backup tanks for every female, because they WILL get aggressive, and most people have at least 1 female that they have to remove from the tank because she's over aggressive. Sororities are very fun and worth it, but they are also a lot of stress and work. They tend to cost $150+ In just a 10 gallon. In a larger tank it would probably be $300+
So, still want a sorority?