Tell me about gorgonian coral

[gregzz4]

I have what I 'think' is a Plexaura flexuosa, but I'm not sure
Medium height in tank and medium flow

Every couple of months it closes up for days at a time and I have to scrub off the brown algae. I use a toothbrush with the gorg in my palm and scrub against my hand. Then it opens again like nothing happened

Crazy polyp extension the rest of the time and no care required otherwise