Most species will adapt to a range of water conditions so long as the water is clean and well aerated. Extremely high pH (e.g. over 7.6, or 8 for hardy species) and very hard water should be avoided.
Most tetras will fade in color if they are stressed or uncomfortable with their surroundings. (But note that many lose all their color at night, which is not a cause for alarm).
They are schooling fish and will not be happy unless kept in a group of at least four of their own species.
Larger tetra species such as buenos aires tetras, congo tetras, serpaes and others can be mixed with quite large tank mates.
Compatibility: Tetras, Rasboras, Danios, Dwarf Gouramis, Rainbowfish, Livebearers, Corydoras and small Plecos.