Many people do run air stones in their planted aquarium, but only after lights out if they inject CO2. This helps get rid of the CO2 and provides oxygen for the fish. During the day, it does just the same, but you don't want that to happen then. Just a little surface agitation should be enough. If everything is balanced during the day, you have harmony between CO2 being injected and produced via respiration by the fish and the plants using that CO2 to produce oxygen that is used by the fish.