What is this green stuff?

[dmolavi]

Can anyone ID this green blob? That's the most pronounced patch, though there are others in the tank (not as dark).

 

[dmolavi]

Some more info:
Ammonia: 0
NitrIte: 0
NitrAte: 5
Phosphate: 0
Calcium: 420

Lights are low power LEDs (this tanks is FOWLR for now) that are on for 7hrs/day.

I haven't yet tried to remove the growth, as I don't want to encourage the spread if it's a nasty. This is on the top of my rock.

 

[erichm20]

How old is your tank? I remember about 6-8 months in seeing bright green patches like that. It eventually went away. I dont know what it was I just chalked it up to some random algae bloom.

 

[dmolavi]

How old is your tank? I remember about 6-8 months in seeing bright green patches like that. It eventually went away. I dont know what it was I just chalked it up to some random algae bloom.

It's going on 4 months. I have seen reports of green coralline algae...not sure if this is it though. I will try scraping it off during my next PWC.