Cardinal Tetra
Paracheirodon axelrodi
Family: Characidae
Cardinals are like Neons' cooler older sibling—the red stripe runs the full body length instead of just halfway. They need warmer water and are pickier about parameters. Worth the extra effort if you can keep stable acidic water.
Water Parameters
Temperature
pH Level
Hardness (dGH)
Care Tips
More demanding than Neons. My Cardinals looked washed out for weeks until I added Indian Almond leaves to lower pH. Blackwater extract works too. Don't add to a new tank—they need mature, stable water.
Feeding
Same diet as Neons but they seem to prefer frozen foods over flakes. Bloodworms are like crack for Cardinals—they go crazy.
Breeding
Nearly impossible in home aquariums. Most are wild-caught from the Rio Negro. I've never even attempted it—the water chemistry requirements are extreme.
📚 Sources: Care parameters based on SeriouslyFish, FishBase, and Aquarium Co-Op. Personal observations from the author's 5+ years of fishkeeping experience.