Leather Corals Turning black??!

[BlackiceClowns]

Hi everyone
I recently bought a handful of leather corals from an established reef tank that the guy was shutting down. The tank looked a mess and the corals were all closed up. I brought them and some cleanup crew home with me. After adding all the corals, a few of the leathers began turning black and dying. Before I knew it I picked one up to move it and it was mush. Another on has turned black now.

Furthermore I added some of the clean up crew an urchin and an snail) into my existing tank that has a leather in it. This tank has been running for a year and a half with minimal issues. Now another leather that I bought a week ago, that was bright green is also dying and becoming black.

WHAT IS GOING ONNNN

 

[Mr. Mojo Rising]

Leather corals like and need good amount of flow. They are adaptable to lighting, but I find they do better in higher lighting, but most important is to give it good random flow.