1st let me say it is awesome that your teug has grow so much in a month. Wow!
If I was a fish, I know hyperactive fish crashing into me would stress me out. Lol. Maybe he is stressed from growing so much? Haha who knows. Elephant noses are cool though. Have they always been in the tank with him or are they more recent?
Aren't they elephant noses slightly electric? I am not sure if this would cause problems though. I don't think so, but I do not know much about them.