If that area is that rusty, you might consider looking at your heating element also. It is under that black plastic cover just above and to the left of your anode. It requires a very special socket to get it out. A normal will not fit because the walls of the socket are too thick. It is a 1 1/2", and requires a thin wall socket. That is the hard part to find. You usually have order it from a RV parts dealer, or Amazon. I got mine from there and it is a Camco, Screw-In Element Wrench. It is designed to use a screwdriver to loosen the element. It is also good for using on your home water heater to check or change the element. The cost is minimum, about 8 - 9 dollars.
2012 Dodge 3500 Cummins Crew Cab 4X4, "Decluttered" and Tuned/2013 Forrest River Viper XLR 390V10 Toy Hauler/2012 Harley Davidson Ultra Glide CVO.
Full time RVer.