The saying “the right tool for the right job” is also true in the case of small fish tanks. You need the right fish for a small tank.
If Flipper was in your bathtub neither of you would enjoy the experience. The same is true if you have a small fish tank. The species you choose is critical to the enjoyment of your fish tank.
Finding the Right Fish for a Small Tank
The smaller your tank is the smaller your fish need to be. You need to think about what species are right for your tank.
Take into consideration the amount of water it takes to fill the tank. A tank that contains one gallon of water will support a total quantity of an inch of fish. By quantity, this means the actual number of fish not the fish size.
You will want to study up on the different species but here are a few suggestions of fish for a small tank. Guppies, Bettas, Cyprinids, Tetras, Platy or Catfish are good choices.
It should be noted however that if you get a Betta, only purchase one male as it is very territorial. If placed with another betta they will fight until one of them dies.
An enjoyable way to exercise a Betta and provide you with some amusement is place a mirror in the tank. The Betta will take an aggressive posture and try to fight, as it believes it is another Betta infringing on its territory.
A word of caution however, because of the aggressive nature if you do not remove the mirror the Betta will continue to fight with it and possible stress itself to death.
You can always place a divider in the tank if you want more than one betta.
How to Maintain the Species in the Tank
In your research of fish for a small tank, choose species that are compatible with each other. In most cases, two or three species should be sufficient.
Knowing what you need for maintaining the species has to be a consideration also.