The cardinal tetra is very popular for its bright colors.  It is more colorful than the Neon Tetra and can be distinguished by the full red lower body.  It originally came from Columbia and Venezuela.  The tank should be well established as Cardinal Tetras are very susceptible to water quality changes and ammonia build up.  After they adjust to a new tank, they are quite hardy and do not suffer from disease the way Neons do.  They appreciate blackwater conditions, which refers to the soft dark water created by the accumulation of decaying leaves in slow moving and still waters.  This can be replicated by filtering through peat or by adding blackwater extract sold by suppliers such as Tetra.  This will turn the water an amber color.  Cardinal Tetras are a schooling fish, so 6 to 10 are recommended, which means a tank of 20 gallons or more is best.  They will lose their color if they lack companionship.  A dark substrate and dark background help bring out their color.  Cardinal Tetras appreciate low light levels and lots of plants.  They are an extremely peaceful fish and don't compete with other species.  They eat small flake foods, freeze dried bloodworms and live foods, such as brine shrimp.

Females are larger and wider than males. Cardinal Tetras spawn on flat surfaces, such as plant leaves.  They prefer low light levels  for breeding, such as dusk and dawn.  The water should be at around 75F with a pH of 5 and a dH of 2, which is very soft.   Blackwater extract will greatly increase the chances of success in breeding.  Up to 100 fry will  hatch in just over 24 hours.  Be sure to remove the parents from the tank before the fry hatch.  The fry will be able to eat finely ground flake foods in about 4 days.  They will quickly become interested in brine shrimp too.

Cardinal Tetras are intolerant of malachite green, which is one of the main ingredients in Quick Cure.  Quick Cure should only be used with Cardinal Tetras if ich is actually present and the dosage should be reduced well below recommended levels.  Otherwise the cure will be worse than the disease.  

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