[at-l] OT - Copper Stains

[janl2 at mindspring.com (Jan Leitschuh)]

Does anyone out there, in all their wisdom, know how to remove copper stains from a bathtub?
I'm serious.

If you reply to the list,cc me directly.

Gracias,
Jan

PS With about five minutes of scrubbing in a very small spot I can remove the stain/deposit. 
But, life's too short!
It's a new bathtub.
I tell myself the green doesn't matter, but it's driving me a little crazy.

The pne tree  water here is acidic, and may be leaching the copper from pipes, although as near as I can tell all my pipingunder the house  is PVC and the interior connections are plex. But there may be some coper in the well pump parts, or ???.