Water has a limit on how much oxygen it can carry and water also has a natural way (gaseous diffusion) to absorb oxygen from the air.
As long as the water is exposed somewhere to the open atmosphere it will absorb oxygen and always attempt to reach a maximum level. While it never hurts to add aeration, it does beg the question of why it's needed.
Are your fish gasping in the tank and hovering near the surface or did you take a test and find out the oxygen is low? If not then why add aeration?
OTOH, if this is an attempt to make the BB more efficient, then it's a marginal benefit which might be better addressed with added media or different media.