Abstract: Our invention relates to the feeding of sodium to aluminum containing silicon as an alloying element in hypoeutectic percentages by flowing the molten aluminum through a trough and feeding a tube which contains sodium within it into the aluminum in the trough, the tube being preferably fed in countercurrent direction with special mixing and a protective surface coating for the flowing molten aluminum. The invention appears primarily applicable to casting large masses of aluminum such as are used in the melts which produce aluminum ingots for sale to foundries.