We aerify BEFORE the graden for some of the reasons above. Filling the aerification holes with sand BEFORE the graden ensures that sand is going into the holes, not thatch and organic. Running the graden AFTER aerification allow us to make sure the we are not removing areas where the graden has already been. After the graden has been through, we cleam the surface with levelawns and blowers. I will get a pic up when I get a minute.