I have a used rainsoft softening system .it has been disconnected for about two years. Before that it was working fine. Before I hook it up to my new home what would have to be done with it to make sure it's running properly. There are two tanks besides the brine tank . I assume one is a carbon filter tank and the other is a resin tank. Do I have to change any of the resin or carbon,in these tanks? What yearly maintenance is preformed on this equipment ? What is the life span of these systems? How often do you have to change the carbon,resin in this system? I have looked on line for a maintenance manual for this system but I have had no luck in finding one. I have spent many hours on line trying to find this stuff out. Thanks for taking the time to look at this post.