Black Ghost Knifefish and goldfish are not compatible tankmates. While both fish may have similar preferences for water conditions, there are several reasons why they should not be housed together.
1. Size Difference: Black Ghost Knifefish can grow up to 20 inches in length, while goldfish typically reach around 6-8 inches. The significant size difference can lead to potential issues, as the Knifefish may see the goldfish as prey or become territorial towards them.
2. Swimming Behavior: Black Ghost Knifefish are nocturnal and primarily bottom-dwellers, while goldfish are diurnal and tend to swim in the middle or upper levels of the tank. This difference in swimming behavior can result in stress for both species, as they may not have enough space or suitable territories within the tank.
3. Water Temperature: Goldfish prefer cooler water temperatures, typically around 65-72°F, while Black Ghost Knifefish thrive in warmer waters between 75-82°F. Maintaining a suitable temperature range for both species can be challenging and may compromise the health and well-being of one or both fish.
4. Aggression and Compatibility: Black Ghost Knifefish are generally peaceful but can become aggressive towards smaller fish or those with long, flowing fins. Goldfish, with their delicate fins, are at risk of being nipped or injured by the Knifefish. This aggression can cause stress and potential harm to the goldfish.
Considering these factors, it is best to avoid keeping Black Ghost Knifefish and goldfish together in the same tank. It is crucial to provide suitable tankmates for each species to ensure their health, well-being, and compatibility.
If you are specifically looking for tankmates for your Black Ghost Knifefish, it is recommended to choose species that have similar preferences in terms of water conditions, size, and swimming behavior. Some suitable tankmates could include larger tetras, barbs, rasboras, or other peaceful fish that can coexist with the Knifefish without being seen as prey or posing a threat. However, always research the specific requirements and behaviors of any potential tankmates before introducing them to the tank.
Personal experience: I have kept Black Ghost Knifefish in the past and learned the hard way about their compatibility with other fish. Initially, I thought they would be fine with goldfish due to their similar water requirements. However, the Knifefish became aggressive towards the goldfish, stressing them out and causing fin damage. I had to separate them to ensure the well-being of both species.