If your anode is corroding fast, it's doing what it's supposed to do. If you are having a rotten egg smell, it may not be the water heater causing it. If you are connected to a well water system, the source could possibly be the groundwater. A water softener can be another source. We had it in a previous deep well over 300' deep. After several years, it went away on it's own. You can use the appropriate filter for treatment.
Causes of the smell and treatment discussed here:
causes of sulfur smell and more info. here:
Hydrogen sulfide info.Hydrogen sulfide can attack a magnesium anode. High pH (alkaline) can also. Info. here:
Water heater anode corrosion Don't know if low pH is hard on an anode, but I believe low pH (acidic) can promote hydrogen sulfide in a HWT.
If you are staying in the same location most or all of the time, I would take a water sample to a lab and get it tested so you will know if there are any issues with quality. You can't take a sample to a lab for hydrogen sulfide though because it is volatile and will be gone by the time the lab gets it. I don't know if there is a simple on-site test for it, but the smell is unmistakable. You need to get sample bottles from a lab first.
Around here, our city water is very soft since it is supplied by a dam. The water is also buffered to a neutral pH of 7.0. Our "dug" well water at home is on the hard side due to calcium.
