3 months ago I put in a new electric hot water heater. Changed over from an old oil boiler. After about 2 months I started to get that rotten egg smell and discolored hot water. The cold water is fine. I have a well and there is no sulpher smell or taste in the cold water. I changed the anode rod from the factory magnesium to an aluminum rod. That did not work. I have flushed the tank 3 times now with bleach. Letting the bleach sit in the tank for 2 hours then running the bleach thru the pipes for 15 minutes than draining and flushing the tank again. This works for about 2 to 3 weeks than the smell and discolored water is back. Does anybody have an idea or solution to this problem.