Tetras are freshwater tropical fish. More than likely, an aquarist has housed a tetra in his or her tank. Tetra fish are diverse. The more common species are the neon tetras and the cardinal tetras though there are many more. Tetras are a schooling fish. The neon tetra is not aggressive. They are very small in size. They should be kept in a tank with fish of the like temperament but these fish shouldn’t be too large either. They should be schooled with at least ten other fish but preferably more. Tetra fish lifespan is only a year, and maybe a few years if desirable conditions are met. Tetras aren’t particular eaters. Neon tetras will do just fine on flake food. Although live food and frozen food is always a treat. Tetra fish require a water pH of no higher than 6.5 and little to no hardness. Tetras prefer an acidic environment. Neon tetras are sensitive to bright light. As a fish owner you want to make sure there are plenty of things the tetra can use to hide itself.