Nutrients vs. Nutrition
The word "nutrient" and "nutrition" are commonly mixed up when talking about reefs. Skimmers (in this case, air bubbles) only remove nutrition, which is fine if all you have is fish, but skimmers/bubbles have no affect on nutrients. "Nutrients" are Inorganic Nitrate, Inorganic (Ortho) Phosphate, Ammonia, Ammonium, and Nitrite. Matter of fact, if you took a fresh batch of newly made saltwater and put a skimmer in it, then added pure nutrients, the skimmer would not have any skimmate at all. Algae, however, would start growing out of control. If, however, you added nutrition (phyto, plankton, ground up flakes, etc) to that same batch of saltwater, the skimmer would go crazy and remove it all.