I do not turn off anything when I'm feeding my fish. Does the ocean turn off its wavemakers when it comes time for the fish to feed?
I do, however, feed out of a turkey baster (used for this ONLY) and target feed my fish. The second it goes into the water, they zoom to it and start "sucking" on it like a baby bottle. Saves a ton of food from being spread all over the place. After they eat for a few min this way, I'll dump the last few specks into the tank so that my crabs have a bit more to chew on.