my 12 inch black ghost has been going off his food lately. For some time he was eating hikari massivore pellets and once they run out i had him on hikari gold sinking pellets untill one day he just refeused them. After about a wk i got him some more massivore which he seemed to love up untill a couple of days ago. Now he is refusing both pellets i offer to him. Should i just stave him for a few days? i was thinking to get him some fresh prawns or fish tmrw to see if i can get him to eat something. is it ok to feed salmon to my fish?