What is this, please

[Charlie G]

Hi. Can someone help me identify this. It has been growing on a coral gray I received about a month ago. It appeared sometime around 1-2 weeks after I had it. I pulled it off and it grew back again.
Is it harmful to my tank and inhabitants?
Do I need to do something?
Thank you.

 

[Eagle_Steve]

Hi. Can someone help me identify this. It has been growing on a coral gray I received about a month ago. It appeared sometime around 1-2 weeks after I had it. I pulled it off and it grew back again.
Is it harmful to my tank and inhabitants?
Do I need to do something?
Thank you.

On my phone, but looks like some type of dictyota macro algae.

If it is, it can become invasive (depends on the type) but is easily dealt with.

@WheatToast or @Subsea may be able to get a better ID for you, as they may be at their computer.

 

[Rick's Reviews]

Definitely edible

 

[WheatToast]

On my phone, but looks like some type of dictyota macro algae.

If it is, it can become invasive (depends on the type) but is easily dealt with.

@WheatToast or @Subsea may be able to get a better ID for you, as they may be at their computer.

+1
You can really see from OP’s images why it is commonly called y-branch algae.

+1 You beat it to me!

Looks like the brown macroalgae Dictyota, which can give off a blue iridescence. It is generally seen as a pest macroalgae outside of dedicated macroalgae tanks and can clog pumps. It really is a shame since it looks so beautiful, in my opinion .
https://www.reefcleaners.org/nuisance-algae-id-guide

Dictyota dichotoma:

 

[Charlie G]

Wow. I haven’t noticed the iridescence. Will read your article in a few thank you.

 

[WheatToast]

Wow. I haven’t noticed the iridescence. Will read your article in a few thank you.

No problem. Iridescence is not present in all individuals (all images used in my previous post display variations of the same species).

 

[Charlie G]

Thanks for pointing me to the article. As it is growing from a coral gray seems like the treatment is picking it off (manually or with a dental pick).

 

[Charlie G]

Sorry meant to write coral frag