Would it be better for a grobo to be near an open window for fresh air or would a room with no real outside air be preferred? Would I have to worry about pollen in the air if I open my windows?
I wouldn’t worry about outside pollen unless someone is growing male cannabis outside your window lol. As far as air, as long as there is fresh air circulating in the house you should be fine. If it’s really hot in your region, an open window with fresh air will definitely make your plant happier.
As rouleauj pointed out, the only pollen you need to worry about is the male cannabis plants, and you should be ok there with an open window. As long as fresh air is available in the room, open window won’t matter much.