<p>An air bath (10) has air outlets (22) extending around the side walls (16) of the water basin (12). Air is delivered to the air outlets through a ring-like air manifold (24) coupled to a blower (26) by conduit (30). The conduit has a bypass vent (80) that siphons off a portion of the air flow otherwise passing to the air outlets and maintains the blower in communication with ambient air. The air delivery system provides a wider range of bubble densities by allowing the blower to operate at lower speeds without overheating or stalling from back pressure arising from the pressure head of the water in the basin.</p>
