 Tankmates should be chosen to be peaceful, not too large, and a more natural display results if the companion fishes chosen are other South American species.An aquarium containing large shoals of lemon and cardinal tetras makes a particularly stunning display, the blue and red of the Cardinals contrasting with the brilliant yellow and black of the lemons.While the preference of the lemon tetra with respect to water chemistry lies within the realm of soft (hardness less than 8° dH) and acidic (pH around 6.6) parameters, the species is notably hardy, and will accommodate itself to a wide range of conditions, the pH range for the fish being from 6.0 to 7.4.