country water / anode / Suburban / smelly water ?'n

My original magnesium rod lasted two years with no odor before it was used up. Replaced it with alum/zinc. After 5 there was no odor until this year. Then odor became pretty bad. But barely any of metal rod gone. That makes me believe it was not doing much sacrificing. Replaced it with another magnesium rod and no odor ..... yet.

The rods are not expensive. I would replace it with another magnesium rod and see if the odor returns. If so, then look at other options.