When target feeding corals, be sure to turn off any water pumps and pre-feed all of the fish, especially tangs. Because most corals eat very slowly, they are often robbed of their food by hungry fish and invertebrates. Tangs are especially troublesome in these situations, as they will bravely poke their heads into coral polyps to get a piece of shrimp or other food item. Excessive water flow also robs corals of food, but this is a problem that has a simple solution, turn them off. Interestingly, if you turn the pumps off every time you feed the tank, the corals will also respond in anticipation of the food by swelling up and opening their polyps to expose tentacles.