New Scientist put up this article covering findings of how reefs survive in nutrient poor systems, such as the ones we tend to keep (skimmers, etc)...interesting...
O'kay folks. Help me out here. Since corals are the primary reef builders, not sponge, what mechanisms pass the nutrients collected by super-efficient filter feeding sponges to the coral animals that ultimately build the reef? What unlocks the nutrients: sponge reproduction? sponge predation? sponge disintegration at death? Would having more sponges and feeding them more plankton enhance coral growth in captive systems?