Black fuzzy algae

[blackjack]

Hi, I’ve got some live rock I inherited in a qt, one of the pieces has this black fuzzy....turf algae? Any ideas? Recommendations for how to get rid of it? Thank you very much!

 

[Benjammin]

My money is on GHA. But I’m guessing.

 

[stacksoner]

Does it smell like decaying organic matter or does it smell like the ocean?

Sometimes there is lots of die off when transplanting live rock from one system to a totally diff one.