Leather turning black?

[BlackiceClowns]

Hi guys my dad recently setup a new tank, and it's been up and running for about 2 months now. We recently added our first corals which were a load of soft corals from a person who was shutting down his aquarium. When we bought the leathers they were all closed in his setup. After a day in our setup this particular leather opened up, but after three days has gone completely black. Is this the leather shedding?

 

[Mr. Mojo Rising]

Leathers like good amount of water flow and light, they also like nutrients in the water. Can you share your water parameters and type of lighting and flow?