SPS frag dying?

[noirsphynx]

I just noticed that one end of a liitle frag I bought several weeks back is starting to turn white. Is it dying and should I try fragging what's left of it? It was under an 8 bulb T5 fixture and I have a 6 bulb T% so I don't think it's the lighting.
I'm also not sure what kind of sps it is either, some kind of Monti? It's a bright greenish/yellow color with orange polyps. The picture doesn't show the color well.