Cardinal Tetra and Otocinclus Compatibility Overview
Cardinal Tetra and Otocinclus can generally share an aquarium with appropriate planning. Both species prefer overlapping temperature and pH ranges. Both species are peaceful, and neither poses a major aggression risk to the other. A minimum 20-gallon tank is recommended to provide adequate territory and water volume for both species.
| Factor | Cardinal Tetra | Otocinclus | Verdict |
|---|---|---|---|
| Temperature | 73โ82ยฐF | 72โ82ยฐF | โ 73โ82ยฐF |
| pH Range | 4.5โ7.0 | 6.0โ7.5 | โ 6.0โ7.0 |
| Temperament | peaceful | peaceful | โ Compatible |
| Adult Size | 1.5 in | 1.5 in | โ Similar |
| Min. Group | 6+ | 4+ | See below |
| Min. Tank Size | 20 gallons (for both species) | โ | |
Compatibility Positives
Caution Points
Species Profiles
Cardinal Tetra โ Paracheirodon axelrodi
Brilliant red-and-blue schooling fish from the Rio Negro. Prefers soft, acidic, warm water โ a natural companion for discus.
โ Full Cardinal Tetra care guide
Otocinclus โ Otocinclus spp.
Tiny algae-eating catfish that are peaceful with all species. Need established algae growth and biofilm; sensitive to ammonia.
Frequently Asked Questions
Can Cardinal Tetra live with Otocinclus?
Yes, in a well-planned setup. Cardinal Tetra and Otocinclus can generally share an aquarium with appropriate planning. Both species prefer overlapping temperature and pH ranges. Both species are peaceful, and neither poses a major aggression risk to the other. A minimum 20-gallon tank is recommended to provide adequate territory and water volume for both species.
What tank size do I need for Cardinal Tetra and Otocinclus together?
A minimum of 20 gallons is recommended for keeping Cardinal Tetra and Otocinclus together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Cardinal Tetra and Otocinclus?
73โ82ยฐF โ inside Cardinal Tetra's 73โ82ยฐF and Otocinclus's 72โ82ยฐF.
Is a Cardinal Tetra aggressive toward a Otocinclus?
Cardinal Tetra is peaceful and Otocinclus is peaceful. No major aggression issues are expected between these species.
Related Compatibility Guides
Tank Size for Cardinal Tetra and Otocinclus
Use the scenario that matches the actual group sizes and temperament you plan to keep.
| Scenario | Tank | When it applies |
|---|---|---|
| Minimum viable | 20 gal | Only for the recommended minimum groups, mature filtration, and close monitoring. |
| Recommended community | 29 gal | Adds territory, swimming room, and a safer buffer for behavior. |
| Low-conflict setup | 55 gal | Best when keeping larger schools or reducing territorial pressure. |