You will see the fish I have in my 10g and the x-ray tetras don't ever eat the flake food I offer them but the red eyed tetras gobble it up. The x-rays will just stay at the bottom motionless while the other fish are getting the food. But the x-ray tetras seem to like and eat the corys food which is sinking wafers and they seem to get at most of it before the corys have a chance even though I split the wafer into three parts and spread it out through the tank. Why are they refusing the flake food?

My angle fish are greedy little things, they eat the flake food at the top, then the algae wafers at the bottom