wound on iridescent shark

Question
I have a I.shark with a loonie size wound cause he constantly rubs on the glass {i have him in a 233 gal tank now with other fish he was in a 85 gal tank for about 1 half years but before that was a 35 gal he is about 12 years old and is 18 inches long }when he gets agigated he thanshers around and of course hits things i only have what i need.Would a red parrot fish be ok with him just wondering thanks for being there too any suggests to solve the promblem would be grateful too so thanks Denise

Answer
Denise,

I noticed the title of your note.  Having answered an entire 5 questions here, already, I was unaware we had titles and/or a subject line in inquires. :)

No need for a followup letter.  This should answer your question better.

As evidenced by this video, http://www.youtube.com/watch?v=eiM4YjTGI2I you should be able to notice that they feed their shark (which is actually a catfish) live food.  Your shark is capable of digesting quite a good-sized fish at his size, so I recommend putting in a fish that is size-notable with him.  

The Red Parrot may or may not be a suitable tankmate, depending on its size.

The threshing will never go, probably, and is due to his captivity in an aquarium.  He is outgrowing his surroundings.

Good luck!  I truly hope this helped.