
They are slow, graceful swimmers. Choose tankmates that are not nippy or inclined to chase the fish as it will not be able to swim quickly enough to get away. Even though they are peaceful fish it is not recommended that you keep them with smaller fish, as the knife will sometimes harass them.
Be sure to provide a cave or tube that allows the knife to hide. They are secretive fish and will become stressed if unable to find a secure hiding place. They are sensitive to poor water quality, and so require excellent filtration and regular aquarium maintenance.