I have read a little bit about some industries deaerating water used in boilers made of iron to prevent them from becoming damaged. I think this is because removing dissolved oxygen from the water lowers its redox potential. I think that this works because once the redox potential of the surrounding environment is lowered past a certain point it is no longer possible for Fe+2 to oxidize into Fe+3. Am I right about any of this? I was also wondering about the reverse reaction, I have read a little bit about using electrolysis for this. If I had some other method of lowering the redox potential of the system far enough would the Fe+3 go back to Fe+2? I'm sure I shouldn't be I'm sort of thinking of this as a parallel to melting point/boiling point.