Can anyone narrow down what this is?

[Donewiththisplace]

I'm thinking bryopsis....?

 

[Username Invalid]

GHA- green hair algae

 

[ourcoralreef]

Yup its hair algea

 

[smallreef]

if its just concentrated to that one rock, take it out and soak it in 50% tank water 50% hydrogen peroxide for 5 minutes or so. it will turn white and die within couple days.

 

[reefiness]

Is this narrow enough for you?

 

[rich]

either way they suck. Good luck getting rid of it

 

[ZippysFunLand]

Mexican hermit crab may clean this up for you. Your milage will vary.

 

[ourcoralreef]

Blennys are good
Tangs are good
Emerald crabs work
Sea hares work
Depending on what else you have in your tank and tank size
Also fish compatibility
Is it just that rock or is it everything
You also need to locate what is giving you that extra nutrients