""CC will not stir up the bottom, and can help keep things cleaner."" How do you define "cleaner"? How are they cleaning?
BG bluegill mixed in with RES is a big problem especially when buying from "traveling" fish trucks and should be a major concern for a pond primarily for swimming. The larger the stocker RES the easier it is to correctly identify them. Sunfish at 2"-3" are very hard even for those with experience to visually separate. RES at 5"-7" are pretty easily recognized from other sunfish when the identifier has some training.
Eating dead fish and some other forms of detritus that could reduce water quality and increase BOD or anoxic conditions.
