My hybrid striped bass have not gained weight on the aquamax and look skinny. They don't feed on it with much vigor and so on a friends advice I'm switching to skreeting 48 percent protein. The pellet size is about double that of aquamax 600. The cost is about the same. His concern is that they may be using more feather meal in their product. He thinks fish do not digest feather meal very well. All I know is that my hybrid stripers don't look they are being fed at all.