Also I don't really understand what you mean by Fe2+ ions. I would have thought that could only occur if the Fe2o3 disscoited but I wouln't have thought that would be the case and wouldn't adding OH ions give Iron Hydroxide?
I meant if you managed to get a Fe3+(aq)
solution from your nails (eg adding acid and oxidising) then you could add hydroxide ions (eg NaOH) which would give you Fe2
doesn't exist - only the iron(II) hydroxide exists).
If I were you, I'd wait for someone else to give you advice on the KNO3
. If you do end up losing/wasting some of your precious iron you could go looking around for some rust (Fe2
) somewhere or 'borrow' some Fe nails (or other iron stuff) from somewhere!