Loaches Online Forum

Hi I was wondering if anyone could help me. I have a 38L tank with a black ghost knife, two Damios and a zebra loach. My zebra loach has gotten significantly larger as of late and so has my black ghost knife. Lately he has been chasing the other fish around the tank and when my black ghosts knife is eating he circles around him very fast and sometime follows and slaps at his tail. My ghost knife is fairly larger and he is just longer than an iPhone plus, but he gets very jumpy when my loach does this and I'm worried he's attacking him. I've had the fish for a long time now and they've never shown aggression to each other. In fact I had an aggressive balloon Molly who killed every fish in my tank including his mate and he had to be taken out of the tank as he was trying to kill my loach and ghost knife. Since then the two fish have been inseparable but now that my loach is growing he's attacking things in the tank. Is there anything I can do or is there a reason he's attacking them?

Basically, your tank is too small.

Your loach would best be kept in a group of 6 or more, but that would require at least a 100 liter tank. However, a knife fish is expected to grow to 35 cm or more, so for that fish the tank is far too small too.

They are fighting for territory and do it as they cannot broad it in any ways. Try replsacing your tank and see what happens.

You have two bottom dwellers in a small space. Loaches need a group of their own kind to bicker with or they will
find someone to bother. Yes, tank is much too small and loaches need to be in groups.

In any case thank you for helping me.