@Janet,

Some caution here is warranted. Chlorine, no matter how high, would not normally removed metal stains. The only mechanism I can think of that would allow it to do so is actually destruction of the portion of the pool surface containing the stain. In spite of the fact that that's how acid washing works, it's not always a good thing.


@OEMom,
Removing well established stains is hard. One tactic you might try is to put some Iron Out in a sandwich bag, swim down, and open the bag on top of the stain. Iron Out is quite soluble, so the trick is to keep the pool water off of it enough so that it can work on the stain. Obviously, this is easiest if someone in your family is a good breath holder or has SCUBA gear.

You might want to practice with baking soda, to get the hang of opening the bag underwater, without scattering stuff everywhere (and then having it dissolve).

Also, you don't want Iron Out everywhere: it destroys chlorine, and vice versa.

Another possible way of applying it -- I've done the baggie method, but just thought of this one -- would be to saturate a small sponge in an Iron Out paste, and the slide it out of the baggie and onto the stain. If you then immediately put a brick (pre-placed) on the stain, it would hold the saturated paste sponge in place, while keeping the pool water away.

Good luck!