Gas ballast question

When using rotovap to recover ethanol with a diaphragm pump. (MD 4C NT Vario) is it safe to gas ballast with air? Is an inert gas necessary? Thanks!

Yes air is fine. Those pumps work pretty well. I’ve beat the shit out of them and haven’t seen them fail yet. Although I think I typically run them with the gas ballast closed when rotovap’ing ethanol.