One SPS STN'ing...HELP

[rutz81]

I have about 20 different frags in my tank right now. I have been having a problem recently with one of them. First the polyps started to not extend as much, and slowly went to not extended at all. Now, about 1-2 weeks later, the base is turning white(STN) Every other frag is doing extremely well. I don't see any red bugs on there(I looked with a magnifying lens) I have no idfea what it could be. Is there anyone with any suggestions/ opinions on what be the problem might be??

Thanks In Advance,

Dave

 

[Ti]

frag it

 

[rutz81]

ti: It's gonna be a little ahrd to frag, it is about 1/2"-3/4". Why would this happen??

Dave

 

[Justin74]

Is it next to any lps or softy frags?Maybe gettin zapped by some feeders at night? May want to consider using a fresh batch of carbon if you havnt already, and/or a Lugols dip.

-Justin