Get some shrimp pellets. My Cory's go ape nuts over them. You can also try another brand. My Cory's only eat Wardley's brand. The Aqueon brand....just sat in the tank until I pulled it out. I also only feed mine in the evening. They seem to eat more at that time. All of my bottom feeders love it when I stir up the gravel a little so they can eat the stuff that comes up. Just some more food for thought. Seriously, no pun intended.