Choosing Cardinal Tetra Tank Mates
Good Cardinal Tetra tank mates share the same temperature and pH window, will not be eaten by (or eat) the Cardinal Tetra, and do not compete for the same swimming zone or feeding time. Each pair guide below scores those factors from 0 to 100 and gives the minimum tank size for keeping both species together.
Start with the highest-scoring pairs; anything under 45 is listed so you know what to avoid, not as a recommendation.
Care baseline
Brilliant red-and-blue schooling fish from the Rio Negro. Prefers soft, acidic, warm water — a natural companion for discus.
| Temperature | 73–82°F |
| pH | 4.5–7.0 |
| Adult size | 1.5 in |
| Minimum group | 6 |