In a storage tank for a process liquid, such as a plating liquid for a plating reactor, one or more barriers are implemented so as to define an inlet area and an outlet area, wherein a fluid flow path is substantially determined by the barrier to significantly suppress the migration of bubbles from the inlet area to the outlet area. In particular embodiments, the introduction of liquid into the storage tank is achieved by inlet lines terminating closely beneath the liquid surface so as to substantially avoid bubble generation and to remove moderately sized bubbles that are conveyed in the inlet lines.