I have used both the wand and the airstone and the bettas have been okay with them and yes they do need some air movement to keep the surface from building up a film or dust and make a clean surface to come up to breathe. You will need a control for keeping the amount of air from pouring out in a big blast or tie a knot in the airline and tighten or loosen it to control the airflow (a hassle I will have to say and the controls only cost a small amount) I get 5 controls and 4 T connections and 2 suction cups in a package for $1.49 when I am ordering from Drs. Foster and Smith.
http://www.drsfostersmith.com/Produc...&N=2004+113403 ~ the green one..they work better than the complicated ones and are cheaper by far.
The cheap airstones work as good as the others but they fall apart after so long (all of them) in the water so be prepared with a spare as you will go to clean it off some day and it will go to pieces in your hand.
Phloxface's idea to have the heater right by the divider and have a T connector in the airline and two control lines and an airstone on each side is great!!
Rose
Similar Aquarium Fish Forum Threads
I have a small filter on one side of my divided tank and a regular filter on the other side. I also have an airstone on the side with the small filter. So far it seems to be working well. Before I put the small filter and the airstone on the one side the water was getting covered with film. The air stone is right next to the divider and even sends bubbles to the other side of the divider. 