hi bro,
sad to hear that your sps is not doing very well. don;t worry. they are like that. tendency to develop RTN are more likely for things like hysterix. Once the signs develop there is usually little or nothing that one can do to reverse it. However if your sps still has some pink bits left, why not frag it and leave it at different places in your tank. its still a hit or miss thing but IMO worth trying.
jon