New Red cabbage corral colony not looking good

[Axolotl]

Got this colony about 5 days ago. It shed its skin as most leathers do in a new tank but now im noticing some deteriorating near the base of a few heads. Temp, alk, calcium, ph all that is good other leathers and softies in tank look fine. My question is if this persists which with deteriorating leathers it probably will should I take the rock out in a bucket of tank water and cut off the dying stalks and keep the heads? How do i get off all the rotten chunks stuck to the rock without poisoning the tank again? I say again because its probably releasing toxins into the water slowly as its dying. This just started so the tops look good but i fear its going to spread. I have a hang on emperor 400 that i could run carbon with for a couple weeks. How often should i change it out? Also should i wait on fragging it and run carbon now or just get it out now and frag the dead parts?

 

[Axolotl]

 

[youcallmenny]

The closest I've had to that is an acan frag I bought was knicked by the band saw. The minor tear in one head looked like it was going to cause the head to die. One night later, our two peppermints had cleaned it off dying tissue and it recovered very soon after.