Hi eagles. I don't know anything about saltwater systems. What happened to me as explained in a post I read,

"The shock obviously oxidized the iron, resulting in rust that turns the water brown. Oxidation reactions can be reversed by reducing the product formed using an acid . . . Vitamin C (ascorbic acid)."

If a saltwater system utilizes Chlorine or Shock, or a product that oxidizes the iron in your water, it would seem to me that the Vitamin C would reverse the oxidation for you as it did for me. I don't know if the Vitamin C would cause a problem with the salt process.

My recommendation would be to scoop out a clear container of your pool water and experiment with it rather than adding the Vitamin C to your entire pool. I wish you success. Our water continues to be beautifully clear and we have not added any additional Vitamin C. I'm sure as we add additional water, small doses of Vitamin C will keep the rust color away.