Algae

[reefguy352]

What kind of algae is this red velvet looking stuff

 

[reefguy352]

And how do you get rid of it

 

[jraker]

Cyano. Increase flow in that are and lower your nitrates and phosphates.

 

[MikeyAl]

Okay. Gonna give you a link here. I had cyano growing crazy. I followed this procedure and have had 6 months with no growth.
Also make sure you are using rodi.
http://www.drtimsaquatics.com/treat-aquarium-algae/treating-cyanobacteria

 

[gone fishin]

Looks like Cyano bacteria to me.

Is this a new tank? If so then it will more than likely come and go. If it is in a low flow area you can adjust a power head to get more flow into that area. Good luck just my 2 cents.

 

[Sk8r]

Looks like cyano, which is not an algae, but bacterial, respondant to lighting and tank conditions. The pic isn't too distinct: it's also possible, if it's tight to the rock and won't blow off, that it's the precursor algae to coralline, but I lean toward cyano.