There are several species of fish tank fish that you can buy from the aquarium store. The common fresh water fish tank fish are Puffer Fish, Angel Fish, Barracuda and Tiger Fish. The common salt water fish tank fish are Boxfish, Cardinals, Sharks, Rays, and Jaw Fish. Interestingly, Puffer Fish can be kept both in freshwater and saltwater.
Aquarium owners can also select from brackish water fish tank fish. However, the brackish water fish tank fish require an environment that is almost similar to that needed for salt water fish tank fish except that the salt concentration per gallon is lower. Tropical fish tank fish are the easiest fish to rear. They only need warm water temperatures for optimum activity.
If you are a beginner then it is best to select a fish tank fish that is easy to keep. The choices available to you include Angel Fish, Bassets, Damsel Fish, Goldfish, Cardinals and Puffer Fish. All these fish tank fish adapt easily to the artificial environment and grow very fast.
The number of fish in a fish tank depends upon the capacity of the tank and the size of the fish tank fish. A large fish tank can hold a higher number of fishes than a small tank. It is also easy to distribute nutrients, recycle water and dispose of the waste material in large tanks. However, overcrowding of fish tank fish can destabilize the aquatic environment.
Another important factor for selecting fish tank fish is compatibility. All fishes are not compatible with each other. Predatory fishes can wipe out entire population of small fishes. Hence, you should always keep those fish in the fish tanks that are at least 50 per cent compatible with each other. For example, the Tiger Fish are best kept with fish that are bigger in size than them as they cannot prey on them. Guppies should never be kept with Tiger Fish since they are an easy prey for them.