Dusty room…?

Ok so my room is maybe 20′ x 20′, and it get’s dusty as hell. I have a Ionic Pro air purifier, but that doesn’t seem to help curb the amount of dust that seems to cover everything. Seriously, I could dust a my desk, and when I turn around it can be layered again…is there anything to reduce the amount of dust other than to keep dusting? It drives me mad!!!