Performed 1 system a/c repair and preventative maintenance. Installed hard start compressor saver kit. Added r-22 to achieve factory recommended charge. Added leak seal successfully to attempt to stop refrigerant loss. Evaporator coil was recently changed out for an all aluminum coil. Black mold in air handler and supply plenum. Recommend installing ultraviolet lighting system to kill mold and bacteria. System operating properly at this time.