In accordance with some embodiments of the present invention, delivery systems and methods for delivering a substance in a medium is provided. The delivery system may include a delivery component, an electronic controller, one or more sensors, and a feedback mechanism. The delivery component has at least one reservoir that contains a substance (e.g., a liquid, a drug, etc.). The electronic controller is connected to the delivery component and controls the release of the substance from the at least one reservoir into the medium. The sensors monitor one or more parameters in the medium and provide a signal to a feedback mechanism. The feedback mechanism, in response to the signal, sends an electrical signal that directs the controller to release the substance from the reservoir into the medium, thereby maintaining a desire level of a monitored parameter (e.g., pH, pO.sub.2, temperature, pressure, ions, volume, impedance, dosage, etc.).