Nic knows what he's talking about. I tried shrimp, scallops and pellets but my ray would eat nothing but krill so I listened to Nic and starved her for three days and all she eats now is massivore delight.
you really cant be afraid to starve them for a few days.... my old tiger was starved for a week 3 weeks after i got her and was eating pellets after that.... ive done the same to 5" motoros.... just make sure they are healthy before you starve them.....