An ink delivery system for delivering ink to an inkjet printhead. The system includes a first ink tank, a second ink tank, a main air line having an air inlet and an air outlet; a first air line interconnecting the first ink tank and the main air line; a second air line interconnecting the second ink tank and the main air line; an air pump positioned in the main air line; first and second airflow restrictor positioned in the main air line; an ink circulation line interconnecting the first and second ink tanks; and an ink pump positioned in the ink circulation line for pumping ink from the first ink tank to the second ink tank.