In the aquarium...
Neon Tetras are suitable for the beginning aquarium hobbyist, but they do require that the aquarium environment support their basic needs. In the wild, Neon Tetra generally live in water that is cooler as it is well shaded from the sun and somewhat on the acidic side, ranging from a pH of 5.0 to 7.0 and KH or 1.0 to 2.0. However, within the aquarium environment they can be acclimated to tolerate brighter lighting conditions and pH as high as 7.5 if they are brought into these conditions gradually as not to shock the fish. This is best accomplished by emptying the newly bought Neon Tetra into a container with the store bag water and the fish. Then, every 5 minutes a cup full of water can be added to the container for 20 to 30 minutes. This will give the fish time to adjust to both the water chemistry and temperature of the aquarium system. After this acclimation process is complete the fish should be netted and added to the aquarium and the water in the acclimating container should be discarded.
Once in the aquarium, Neon Tetra should be provided plenty of places to hide if threatened; such as, live or fake plants, drift wood or root structures or large rocks. Due to their size and overall very passive nature, Neon Tetra should only be kept with other peaceful community species that will not grow large enough to eat them. While they reach just over an inch in size when fully grown, they do form tight schools that help give them protection from other larger fish species, so it is strongly recommended that this species be kept in good sized groups which will benefit their overall health and security.