Help with frag

I have a question about this sps frag that I bought a couple weeks ago. It seems that the flesh is deteriorating. here are a couple pics a couple weeks apart, the area in question is on the base of the left limb where it meets the central part. In the first image you can see some algae there, since that pic, the algae is gone but you can see how the flesh is gone. Is the tissue necrotizing? Should I try to remove that limb?





I got the frag for $5 at my LFS and I didn't really inspect it very closely (chalk this up to a learning experience). I believe I bought it like this though, and it is hard to say if the are is growing. But I am hoping that it is fixable.

Also, I am wondering about the downward pointing limb on the right and side...why would it suddenly start growing down like that? Also it doesn't come across as well in the pics, but the limb on the right is visibly different, both in the polyps as well as the flesh. The polyps in the right limb are white whereas on the rest of the frag they are green.

Any help would be appreciated!
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Dip it for a minute or two in Lugols, CoralRx or if either of those two aren't available use tincture of iodine from the pharmacy.
If you use the tincture get a liter of tank water and add 15 drops. Bath the coral for a couple of minutes and then swish it around in another liter of 'clean' tank water.
Do this once a day for a couple of days. If you after a week you don't see improvement in the area that is experiencing the slow tissue necrosis snap that branch off and treat the remaining coral with another bath to kill bacteria in the fresh wound.
The other branch has had an injury of some sort. It's really no big deal and the tissue looks good in the pic. If it were a burden the coral would let the tissue die instead of waste energy to keep it going.

 

Thanks! I will give it a try.

Yeah, other than this area of necrosis, the rest of the frag is looking good (atleast to my untrained eye), it is even starting to encrust the plug at the base.