Metal Smell and Taste From Water

I doubt you have a metal fresh tank. Those went out almost 40 years ago. Draining the Water Heater will not get rid of most of the mineral deposits. You need to drain and then make a small tube connected to the pressure water hose and stick it in the drain opening of the water heater to help break up the minerals and get them loose. Then try to inject about a 1/4 cup of bleach into the drain hole, install the drain plug, fill the water heater and then drain again and keep doing it until clean water comes out. Doug