I am only aware of what I experience with my tanks, and my customers tanks,and what others tell me and what I read. That is as I wrote. I would always recommend scrapings off of any coralline a friend has that grows well. Even coralline that does not grow well under one persons lighting might grow well under yours, especially if the lighting is different. To get coralline from shallow sources I would surmise one would need to get coralline from a tank with corraline that is from live rocks that came from before Florida shut down wild coral harvesting, and that was at least 5 or 6 years ago. It was during and just before that period of time, I have been told and read, that harvesting of deep rock started. One also needs to consider the wave lengths of light at depth is quite different in the ocean than with the minimal depths we deal with in our tanks. There is more blue light and less red light at depths.