If you want a Fish Only With Live Rock l (FOWLR)it may be fine. If you want a reef, you want diversity, and it will absolutely reduce the diversity of microorganisms in your tank, such as pelagic bacteria. Seeing that bacterioplankton is a primary source of food for corals, and corals are literally walls of mouths, suggesting they do indeed like to capture this floating food, I'm not sure why you would want to kill it off. Your corals may be ok, you can throw more light at them and they can get more nutrients from their symbiotic algae. You probably won't see mortality as a result, but that does not mean it is not negatively effecting them. It will cut into the food web.