Eric - have you thought about building a "scud cage"? You could use a fine wire mesh that would keep the breeding adults in but let the recently hatched YOY scuds escape through the mesh. This would protect your adult breeders from predation.
This would be a modified a version of a fish cage, have you had a chance to read the article on fish cages in this months Pond Boss?
Here is another source of scuds, they are located on Ft. Collins CO:
