What is this

[77mfan20]

It's like a plant

 

[Nu-Nu the eel]

Just hair algae! Its fine... Hermits or snails will eat it.

 

[Flaxon-Waxon]

Check your nitrates and phosphates. Emerald crabs eat it up too. But you should figure out what is causing it instead of how to get rid of it. A good way to get rid if is to take out the rocks individually and scrub them with a toothbrush in a bucket of RO water...

 

[willbratz]

Got this link from another regarding hair algae
http://www.saltyzoo.com/HairAlgae.html