Abstract: A plating system and method is provided for electroplating silicon wafers with copper using an insoluble anode wherein the electrolyte is agitated or preferably circulated through an electroplating tank of the system and a portion of the electrolyte is removed from the system when a predetermined operating parameter is met. A copper containing solution having a copper concentration greater than the copper concentration of the removed portion is added to the copper plating system simultaneously or after electrolyte removal, in a substantially equal amount to the electrolyte removed from the system and balances the amount of copper plated and removed in the removal stream. In a preferred method and system, an electrolyte holding tank is provided which serves as a reservoir for circulating electrolyte. The addition of the copper containing solution and removal of working electrolyte is also preferably made from the holding tank.