Black Ghost Knifefish and Red Eye Tetra Compatibility Overview
Black Ghost Knifefish and Red Eye Tetra are generally not recommended to be housed together. The adult size gap creates a meaningful predation risk. Both are semi, so give them a larger, well-planted tank and watch how they settle in. Review the behavior and water details before deciding whether to attempt the pairing.
| Factor | Black Ghost Knifefish | Red Eye Tetra | Verdict |
|---|---|---|---|
| Temperature | 73โ82ยฐF | 72โ79ยฐF | โ 73โ79ยฐF |
| pH Range | 6.0โ8.0 | 6.0โ8.0 | โ 6.0โ8.0 |
| Temperament | semi | semi | โ ๏ธ Monitor |
| Adult Size | 18.0 in | 2.8 in | โ 6ร difference |
| Min. Group | 1+ | 6+ | See below |
| Min. Tank Size | 100 gallons (for both species) | โ | |
Compatibility Positives
Incompatibility Reasons
Species Profiles
Black Ghost Knifefish โ Apteronotus albifrons
The Black Ghost Knifefish is a unique and elegant addition to the aquarium. With a lifespan of 5-8 years, it requires a minimum tank size of 200 liters. It is a solitary fish with a low aggression level and moderate activity. Its slender body and silver-blue coloration make it a captivating sight.
โ Full Black Ghost Knifefish care guide
Red Eye Tetra โ Moenkhausia sanctaefilomenae
The Red Eye Tetra is a popular freshwater fish known for its vibrant red eyes and sleek, silver body. They are generally peaceful and can be kept in a community tank with other non-aggressive species. Their moderate activity level makes them suitable for a variety of aquarium setups. With proper care, they can live up to 5 years.
Frequently Asked Questions
Can Black Ghost Knifefish live with Red Eye Tetra?
Generally not recommended. Black Ghost Knifefish and Red Eye Tetra are generally not recommended to be housed together. The adult size gap creates a meaningful predation risk. Both are semi, so give them a larger, well-planted tank and watch how they settle in. Review the behavior and water details before deciding whether to attempt the pairing.
What tank size do I need for Black Ghost Knifefish and Red Eye Tetra together?
A minimum of 100 gallons is recommended for keeping Black Ghost Knifefish and Red Eye Tetra together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Black Ghost Knifefish and Red Eye Tetra?
73โ79ยฐF โ inside Black Ghost Knifefish's 73โ82ยฐF and Red Eye Tetra's 72โ79ยฐF.
Is a Black Ghost Knifefish aggressive toward a Red Eye Tetra?
The adult size gap creates a meaningful predation risk.
Related Compatibility Guides
Tank Size for Black Ghost Knifefish and Red Eye Tetra
Use the scenario that matches the actual group sizes and temperament you plan to keep.
| Scenario | Tank | When it applies |
|---|---|---|
| Minimum viable | 100 gal | Only for the recommended minimum groups, mature filtration, and close monitoring. |
| Recommended community | 150 gal | Adds territory, swimming room, and a safer buffer for behavior. |
| Low-conflict setup | 220 gal | Best when keeping larger schools or reducing territorial pressure. |