Recently a customer checked his anode and was alarmed to find it was covered by a reddish-brown coating. While the color could indicate some rusting, the coating itself was nothing to be scared about. Many people have told us that they cleaned their anode to get rid of the gooey, slimy, rough surface so it would be smooth again.
Sacrificial anodes start out bright and shiny, but as soon as they are immersed in water, they chemically begin to change. Magnesium anodes are kind of gooey and gritty, while aluminum ones are gooey and slimy. Cleaning them is a really bad idea because it shortens their lives. You’re cleaning off part of the anode that is reacting with tank steel. This post will also be added to Quick, in the Troubleshooting section.