Advice removing water stains on front curtains

Curtains looks good again - and the stains looked terrible before.

Sprayed OxyClean on dry curtains, scrubbed with soft brush and then into washer.

Line dried.

My wife thought the staining might have been mold (from accumulated dust and dirt over the years and then wetted with condensation from touching the windows) so she added Sink-the Stink" (used to clean scuba gear).

In any case, the curtains looked horrible before and now look fine.

Thanks for all the advice and suggestions.