I've had a similar experience trying to catch blue TP from a power supply lake. Also, small BG plague my efforts to catch larger BG. Sometimes I wonder if the BG are needed at all when stocking TP. I mean maybe TP annually with RES might produce as much forage as BG can. Might make targeting TP easier too? Maybe not.

It isn't what we don't know that gives us trouble, it's what we know that ain't so - Will Rogers