What is growing out of my brain coral?

[HenryF]

Hello everyone!

I noticed some greenish “hair” growing on my brain coral frag. I think it’s algae but i just want to be sure, I pulled it off a couple of times but it keeps coming back. It’s growing or coming out on top of the coral so I just wanted know what that stuff is. Also I’ve noticed the coral’s purple coloration has been getting lighter. Any advice or information would be appreciated.
Thank you!

 

[Homelander]

It definitely does not look happy. What are your water para.eters and lighting. And how much flow is it getting?