As I wrote in the newbie forum, not all fish food is created equally. Many simply list fish meal as the main ingredient. Many 'fish meals' are made simply from the waste of fish processing. These fish meals require copious amounts of starch in wheat, oat, soy or rice flour as binder/filler and to increase crude protein levels - often as the first or main ingredient. (This is not unlike some dog foods where corn or soy is the main ingredient!).
The better fish foods are made from fresh whole fish or at least fish meal made from whole fish (rather than waste products).
Buyer beware - Check the label!
