A device for infusing gas into a liquid comprises a housing and a tube having a width that is smaller than that of the housing and which is positioned within the housing such that the longitudinal axis of the tube is approximately parallel to that of the housing. The device further comprises potting compound interposed between an outside surface of the tube and an inside surface of the housing at both ends of the tube. Microporous hollow fibers extend from the potting compound at the first end of the tube and through the potting compound at the second end of the tube. Openings in the device allow for the introduction of gas and liquid into the device. Gas enters the device and into the microporous hollow fibers. Liquid enters the device and is exposed to the outer surfaces of the microporous hollow fibers. Gas passes from the microporous hollow fibers to the liquid and is dissolved into the liquid. Liquid infused with gas exits the device.