My clown tang pretty much only eats PE mysis. I have had him for almost a year now and he just recently started eating nori. I got lucky since my clown tang was eating right away and I have never had any problems with him. I found out (after I already bought mine) that most clown tangs die within the first few months after purchase. Apparently it's very hard to get them to eat and most starve to death
I hope yours makes it and starts eating.