Every filter comes with a lifetime warranty on the tanks and valves.  After the filtering media expires you simply disconnect the system and exchange it with new media.  It is a simple enough task homeowners can do in 35 minutes.  So the filters are virtually reusable time after time.  There are no electrical hookups or high power backwashing, so essentially there is nothing that can go out or break.   The high spun fiberglass tanks are so strong and resistant, as long as it is taken care of there should be no reason it lasts for your grandchildren.