The old oil heater has a magnesium rod as per the manufacturer. The new GE Unit says it comes with a magnesium rod as well. We have had the HW heater in use for 5 months now and if it was something in the HW heater I would think it would have come out by now. But the gel just seems to be coming out more. I am hoping it is just the rod, other than that I have no idea what could be producing the gel?