Congo tetra (Phenacogrammus interruptus) is a timid, but unspeakably beautiful aquarium fish. Probably, it is the most gorgeous fish of the characin family.
A tank, which has tetra fishes in it, should be thickly planted. The majority of these fishes has a very good looking coloring (due to some special pigments they have, that change their color under different kinds of lights).
The fishes look good in a school. To create the space in a tank so, that the whole school is seen and not hidden among the tank plants, it’s necessary to put them thickly almost without any space between the plants.
Therefore, some free space is left around the front tank wall and there the school can swim.