Hi, I have a 30 year old fiberglass pool that has some orange staining on the bottom of the pool by the edges. The pool cleaners have scrubbed it, and have no answer accept to say that the pool is old. I have been looking at some of the threads to try to figure it out. I have seen that you should test the stains by putting crushed vitamin C in a sock and rubbing it on the stain. Not sure that would help under the water though? I have also seen something about blue magic? Also an expensive suggestion to resurface the pool which i’m not sure how that would work since I’ve always been told you could never completely empty the fiberglass pool of water? I don’t know what to do. It looks terrible. any recommendations?