Originally Posted by andrewfrith
You can return the prints to the water and wash them again but this action will probably not get rid of the stain. The stain itself is caused by the formation of iron hydroxide from residual ferrous iron that results from an intial wash in water that is slightly aklaline. Once the iron hydroxide has been formed in the paper it can not be removed by washing. The key is to use an initial wash that is slightly acid. To make it acid, just add a small amount of citric cid, acetic acid, or even vinegar to the first wash.