Well, Chris, everyone's waiting for you, but hesitating to volunteer.

I guess I move to wheatgerm for two reasons. First, following the crowd that says it is more digestible. (I've doubts about that.) Second, it is the one sinking pellet I can obtain that is lower in protein (but not really low!). I recall Bil posting on NI some interesting thoughts that "the crowd" has it wrong... that what we should be doing is feeding protein without carbs and really watching the lipids during winter. As I recall, he suggested moving to a diet of just prawns and whatever algae can be grazed during winter, feeding only what is eaten. Right after that I tried little "cocktail shrimp" left over from a holiday event (no sauce

). The koi did not care for them. They preferred the sinking wheatgerm pellets. So.... I didn't try to force them to accept an unfamiliar food.
Does that give you a jumping off point?