need an ID.. is this bad?

[125mph]

Hi guys,

These green stem things are popping all over my rock structure. I don't know what it is.. should i try to kill it? what is it?

 

[1leftygolfer]

Not sure, but dude, envious of your hardware. How long have you been running the AI Sol Blues?

 

[SKremk]

It's a type of algae called Neomeris annulata

 

[tankaddict]

Harmless, they appear if you have a high Ca concentration.