boardsurfer
Aquarium Advice FINatic
Aim your powerheads down the back glass (from the side). That's how I had mine, and it really grew in those areas.
I have intense light in my tank and coralline grows everywhere. Even the loc-line nozzles that are in 2-3" of water directly under a MH light. I also have coralline growing in my sump with less than 1 WPG of light. I have talked with Mike at liverocks.com and he stated that coralline it more plentiful on the side of the rock that does not get as much sunlight. I am going with "it is true" in nature with real sunlight but in our tanks where it is next to impossible to get the intensity of the sun it is not a factor to be concerned with.I read somewhere here that coraline algae likes less light.