The "rotten egg smell" usually comes from the hoses, not the potable water tank. The most effective way to clean it is to add a hose Y valve to the system (it goes in backwards (see pictures in Hayden's IP Photos.com site) so you can flush out the plumbing without getting the chlorine in the alum tanks. You might also want to rig up a bypass for the hot water tank as once chlorine gets in there you have to do a lot of flushing to get it out.
Top answer your original question, I'd suggest draining both tanks--at least you won't worry about them.
05-29-2008 12:56 PM
Preparation of water system for storage
We are currently in El Salvador and leaving our 380-91 for six weeks. I am triying to decide whether to leave the tank full or drain it down and add a little bleach to kill any bacteria that may grow. I do have the aluminum water tank and I do know that bleach is not good for it. We have done it in the past when we had smelly water. we added a little Bleach for a few hours and then flushed the tank several times and seemed to have ho problems. I am wondering if anyone else may have a better sollution.