"The form, solid or liquid, in which nutrients are added to marine ecosystems is of critical importance in determining the likelihood that the system will be able to assimilate them and incorporate them into the “web of life.” Too much liquid causes an imbalance and sickens the system, and mechanisms will be used by nature in those cases to get rid of the excess, unusable nutrients. The capacity of these systems to make use of solid food input far exceeds their capacity to assimilate liquid food."

"Despite all the uncertainties about the relative contributions to the coral-reef ecosystems of different kinds of autotroph, bacteria, dissolved organic matter, and internal vs. external inputs, it is clear that the phenomenally high total productivity is in large measure due to the combination of a tremendous surface area of photosynthetic tissue (either in the form of zooxanthellae or benthic algae and higher plants), optimal light and temperature conditions for photosynthesis, and the tight recycling of nutrients in an otherwise nutrient-poor environment."

http://www.fisherycrisis.com/coral3.html
http://www.reefkeeping.com/issues/2003-03/eb/