Not to keep the topic off track, but do SPS corals actively feed on particulate foods? Specifically
Acropora sp. corals.
Most of what I have read so far leans towards dissolved nutrient uptake. I appologize for not recalling the source, but I also remember reading an article that claimed no evidence of feeding was or has yet been found in the guts of these corals.
The reason I ask is that after months of feeding Phytoplankton, I saw few if any results. After only a few short weeks of reduced skimming, which allowed my Nitrate level to elevate slightly, I noticed a dramatic shift in coloration and growth in all of my (Acropora sp.) and other SPS corals. My LPS where happy as well, but I anticipated that.