Black growth identification

[jlague]

Can anyone tell me what this black growth is? I bought live rock from a fish stores tank and have been cycling for the past 4 days. The rock came with several bristle worms, and this started growing with some algae. The store also told me I’d be good to put some crabs in at the start so I have 3 hermit crabs and an emerald crab.

 

[fishguy242]

hi welcome to the reef ,looks like an apstia nem

 

[hyprc]

In the left side of the circle I see what appears to be aiptasia in the shadow. Bonus fat bristle worm towards the bottom

 

[Oropher]

i don't think it is an Aptasia, because Aiptasia is clear (glass anemone).
More like a turf algae.
If you can pull out that rock, you can drop some 4% peroxide on the algae, after a few seconds it will produce small bubbles, wait for a few mins then you can put the rock back in the tank. repeat process in the next few days.

 

[hyprc]

i don't think it is an Aptasia, because Aiptasia is clear (glass anemone).
More like a turf algae.
If you can pull out that rock, you can drop some 4% peroxide on the algae, after a few seconds it will produce small bubbles, wait for a few mins then you can put the rock back in the tank. repeat process in the next few days.

You might want to zoom in a little more