A fresh magnesium rod keeps your tank from corroding from the inside out. Over time, these rods get eaten away by minerals in the water, which is exactly what they are supposed to do. Check yours every year to see how much buildup has collected on the surface. If you see deep pitting or heavy white deposits, it is time to swap it for a new one. Keeping a spare in the shed means you will not have to deal with a rusted-out tank when you least expect it.
water heater magnesium rod
Protect your water heater from corrosion.