Look on the ingrediants list. Basically your looking for fish food with no fillers and lots of whole fish. If it just says krill its no better than fish meal. so its garbage. Basically just useless fat trimmings and ground bone. Also if it says "krill" or "fish meal" some of the protein is going to be indegestible so they are inflating there numbers to scam you. First ingrediant is the largest, the last is the least important
Good:
Whole krill meat
Whole salmon
Garlic
Spirulina
Bad:
Wheat
Grain
Fish meal
Krill
Salmon
Any mammals
Rice