The cardinal tetra is a great fish for those new to the hobby. With their striking colors of blue with a red stripe running all the way across their lower body, these fish really stand out in a tank. They also tend to be very hardy and are considered a small peaceful schooling fish that only gets to be around 2 inches in size and can live up to 5 years.
Tank
As the cardinal tetra is a schooling fish you will want to get a minimum of 5, but more is always better for these fish. Also, because of their very active nature, the minimum tank size recommended for the cardinal tetra is 20 gallons, with a pH between 4.5-7 and a temperature range between 75-81 degrees, and they tend to really thrive in a heavily planted tank.
Diet
Cardinal tetras are considered omnivores; however, they are primarily carnivores. So, you will want to feed them a varied diet with foods such as brine shrimp, daphnia, bloodworms, or tubifex worms, along with a high-quality flake or pellet.
Breeding
Male and female cardinal tetras can be told apart often by looking at the blue band along the side, as the females blue band tends to bend upwards. Males also tend to be thinner and more streamlined than their female counterparts.