The Cardinal Tetra is similar looking to the neon tetra with a longer red stripe along the body which is arguably more colourful. Cardinal tetras are happier in soft to medium water areas and are happiest living in shoals. They like to live in an environment with a mixture of open space and dense planting so planting shorter plants in the front pots and taller bushier plants at the back would create the perfect environment for Cardials.
A shoal of 3-7 Cardinals would look great an Avo.
Good tank mates