Adding a few more fish (if you want to?) would help, as they would provide a good portion of nutrition to the corals, but if that's not something you want to do, then I would look into feeding something like TM Phos Feed and ammonium bicarbonate (or possibly urea). Most corals when provided the right nutrition (light and particulate food) will produce their own amino acids, etc. But in a deficient system I can see benefits of adding aminos and carbs, but I would find a long term solution to their replacement, as they can lead to other unwanted issues (like feeding pathogens, etc). So with the amount of biomass in corals, you don't have enough fish to supply them with nitrogen and phosphorus, so you have to be the fish, which is why I like to use organic foods they would find in nature (phyto, zooplankton, Yello Sno and Phos Feed).