I think you're right, the picture doesn't look like a mold issue (I think it's called PLUME ). I think a good cleaning, maybe a little sanding will clean that area up. I would still do a colloidal silver/water wipe down after cleaning though, just to be safe. As for the water stains, there isn't much you can do to get rid of those. Again, maybe a light sand to lighten the stain a bit and a wipe down would make it less noticeable.