Anode rods...Magnesium vs Aluminum

**Its.me.again** · 10-20-2012, 04:31 PM

I actually ordered a spare anode rod for future replacement in my new 30 gallon electric hot water tank. (I had replaced one before in the previous tank. )

But I never know what material is the best to buy. Magnesium or Aluminum? What is the difference? Also, when I cut the new rod...should it be 4 to 6 inches from the tank bottom?

I have ordered aluminum, only because it was cheaper and I like cheap 6 year tanks, too as my water is public water system but it seems to eat the rods fast. I believe it is hard water, a lot of white deposits collect in hot water tanks/ showerheads...etc.

Thank you.

**jadnashua** · 10-21-2012, 04:56 AM

Different metals react differently with the local water quality. As to which is best, it also depends somewhat on the water quality is. Some can react and release gas into the water that comes out when you draw water at the tap. So, as to whether one is better than the other, it is a local decision.

hj · 10-21-2012, 07:42 AM

Magnesium can create an odor, but as a practical matter as far as changing anode rods is concerned, I agree with the plumber I was talking to last Friday. He said the number of anode rods he has changed is ZERO, and I said I had changed ONE. My normal anode rod replacement is a 3/4" brass plug. My experience with them is the same as draining the heater. If you do it, the heater might last 7 years, if you do not, it may only last 84 months.