What about air in the pellets? (Oh Cecil and Bill!!!)

It all depends on what the proteins are made from. For instance, fish meal is more digestible than chicken feathers, but they are both "protein".

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3/4 to 1 1/4 ac pond LMB, SMB, PS, BG, RES, CC, YP, Bardello BG, (RBT & Blue Tilapia - seasonal).