The ghost and clown knife should be started off in a very gentle tank... let them get strong and confident...and then place them where they will be... the ghost knife is great in community tank... they are non aggressive unless the fish are much smaller... and clown knife usually is eating live food when you get them... must be taught to except pellets..and then once it does learn you never go back... mine is 16 inches and lives fine with angels.. he is non aggressive because raised non live food.. so in essence not hard to raise...BGK needs good size tank...but eventually CK needs huge tank....