Abstract: Embodiments of the present invention include photobioreactors with membranes to introduce carbon dioxide into media contained within film photobioreactors. Such membranes can also be used to remove dissolved oxygen from the media. In some embodiments, one or more membrane tubes are welded into a plastic film photobioreactor to make a one-piece reactor. According to some embodiments of the present invention, algae is grown in a photobioreactor using pressure, gas composition, and surface area along with sparging to control the pH in the photobioreactor.