I'm getting way above my pay grade, so I hope any of our northern members would chime in with their thoughts.
Anthropic, I started with 1/8" Cargill, and finished up with 1/4" pellets. As with most fish, they started lightly eating the pellets, but once they settled in it was total chaos. At Todd Overton's advice, I also added FHM's at the same time as the RBT. They wiped those out almost immediately.
I wondered the same thing about stocking them on top of CNBG, and my WAG guess is that they would do well. The CNBG would slow down their feeding with the colder water, and the RBT would thrive at those same temps. I'm not sure if the spiny CNBG would beat them up during seining though.
If targeted for forage, then they only need to be raised until they hit whatever length the majority, or the targeted size, of the LMB you are wanting to feed can eat.
Mark, I stocked them in December both times I had them. The first batch was for fly fishing in the hatchery pond, and I think those were stocked at around a pound a piece. I would think a 1# RBT would be too big for the majority of the average LMB in a pond. Again, only a guess. IIRC, I got 100 for the forage sized RBT, and they filled up both 60 gallon vats on my transport tank by the time I pulled them.
