A good point about here would be to pull out your manual that came with your rig and read it. With a Suburban hot water heater you are to remove the plug monthly, back flush the tank, inspect the rod and reinstall it if it is still serviceable. I have been in areas where the anode rod was completely gone in just over 60 days, thankfully that is a rare occurrence but you never know if you don't perform the factory recommended maintenance.
JimF, CWO, US Army Ret, 100% DAV
2011 Georgetown 378TS
2008 Dodge Caliber Toad