A new well water tank may be the "captive air" or bladder-less type. Should tap water stored in a modern tank of either variety taste like metal, it's probably not the tank. Captive air tanks have an internal rubber bladder that well water moves in and out of, never coming into contact with air. Modern bladder-less tanks typically feature a glass lining or epoxy coating to help resist corrosion.
Well water that tastes like metal could be caused by iron or some other heavy metal in the ground water. It could also be that you have old galvanized or copper pipes through which the water moves to the taps. It's probably not the new well water tank, however.