Manual for Sulfur Filter System

We have a Iron and Sulfur Filter System but we don't have enough information on the upkeep. We have a manual with the last few pages missing and we have no information on the brine tank. Is there anything you can do for us? Is there a manual we could get? Could you tell us where to look, at least? Anything you could do for us would be greatly appreciated.
From your description it sounds to me that you have green sand filter which requires potassium permanganate to regenerate. The most common valves with those filters are either Fleck or Autotrol. The only upkeep to it is make sure you have pot-perm in the brine tank and set the time clock to regenerate every 3-4 days. Other than this I don't have more information.