Hippo Tang won't eat seaweed

[GongShow]

Hey I have a Hippo tang (first tang) for about half a week now and i was told it would eat seaweed of a tank side clip like crazy yet mine wont even touch it it'll graze the rocks and eat that but it's pretty much cleaned 3/4 of it and it'll eat the flakes and pellets i put in. Are the flakes going o be enough to sustain him. Is that normal that he wont touch it and what can i do to try and coax it into eating the seaweed.