“Tree branch” macro ID help

[Nachopapa]

Interested if anybody knows what type of algae this is? It hitched a ride on live rock when my tank was set up and it started to grow on a few rocks. I like the look I just don’t want to get out of control.

 

[WheatToast]

You appear to have some species of Codium, a green, desirable, hardy macroalgae with a spongy texture and may grow branches or in lumps depending on the species. It grows incredibly slowly and invertebrates enjoy grazing on its occasionally fuzzy surface since it attract edible particles (though the algae itself is highly inedible). It is commonly known as “Dead man’s fingers,” “Green fleece algae,” “Finger algae,” and “Oyster thief,” and is said not to tolerate temperates above 78° Fahrenheit.
https://www.marineplantbook.com/marinebookcodium.htm
https://www.livealgae.co.uk/green-macroalgae-species/marine-macroalgae-codium
https://www.lareefs.com/products/codium-lucasii-metallic-blue-and-green-macrolgae-1

By the way, where did you obtain that live rock?

 

[Nachopapa]

You appear to have some species of Codium, a green, desirable, hardy macroalgae with a spongy texture and may grow branches or in lumps depending on the species. It grows incredibly slowly and invertebrates enjoy grazing on its occasionally fuzzy surface since it attract edible particles (though the algae itself is highly inedible). It is commonly known as “Dead man’s fingers,” “Green fleece algae,” “Finger algae,” and “Oyster thief,” and is said not to tolerate temperates above 78° Fahrenheit.
https://www.marineplantbook.com/marinebookcodium.htm
https://www.livealgae.co.uk/green-macroalgae-species/marine-macroalgae-codium
https://www.lareefs.com/products/codium-lucasii-metallic-blue-and-green-macrolgae-1

By the way, where did you obtain that live rock?

Thanks for the great reply! The second link looks exactly like what I have, more brown but exactly the structure

my LFS brought some additional rocks when they helped me set it up this summer. Two of them have it now (took 6 months to grow).