throw the feeders in one at a time so they get used to hitting whatever hits the water, then mix it up with some cut up unthawed krill, when that happens you will be on your way to pellet, but it takes lots of time and patience in most cases
the orino in my avatar still doesnt take pellets and hes around a foot, i can handfeed krill but no pellets lol, there were times were i starved him for almost 2 months and he still didnt take them, my monos started taking pellet at like 8 inches or so, so like i said major patience