also, it's not very healthy to feed rosy reds as a main diet. they contain an enzyme which will strip your clown knife of thiamine (a B vitamin) and can lead to skeletal and muscle development issues i.e. a sick and deformed fish over time. livebearers or cichlid fry you raise yourself would be better choices, as they do not contain the enzyme and are also less fatty. plus when you breed the feeders yourself you know how healthy they are. store-bought feeders often have parasites, bacteria, or other organisms/conditions which can harm your fish. of course, the best option of all would be to get the clown knife used to eating prepared or frozen foods, but that can take time.