Overview
The Cardinal Tetra (Paracheirodon axelrodi) is a beginner freshwater species known for its blue, red coloration. Brighter color than neon tetra. Mid to Lower-Mid.
Origin & Appearance
Origin: South America.
Colors: Blue, Red.
Body Shape: Fusiform (torpedo/streamlined). Typical adult dimensions: 5.0 x 0.9 x 1.5.
Sexual Dimorphism: Subtle; females rounder.
Tank & Water Requirements
| Min Tank Size | 11 gallons |
| Temperature | 73–81°F |
| pH Range | 4.5–6.5 |
| Water Hardness (GH) | 1-5 |
| Bioload | low |
| Oxygen Demand | low |
| Plant Safe | yes |
| Aquarium Position | Mid to Lower-Mid |
Behavior & Activity
Mid-to-lower schooling; slightly deeper swimmer than neon tetra; smooth coordinated school movement; prefers shaded paths
Speed: 42/100Aggression: 1/10diurnalSchooling (8+)
Breeding
Difficult; egg scatterer; needs soft acidic water
Common Diseases
💊 NTD💊 ich💊 sensitive to water changes
Expert Notes
Brighter color than neon tetra