Id algae and a pest.

[BigHildy53]

Need help identifying a red velvet, soft, type of growth on some of my rocks. It's not on the sand, rocks only. I'm thinking it's cyano but would like to confirm.

I also have a new visitor. Lower right corner of the first picture.

 

[oneofmany]

Yeah, it looks like Cyanobacteria to me as well. That visitor you have is an Aiptasia.

http://reefkeeping.com/joomla/index.php/current-issue/article/33-reefkeeping-101-

 

[DeepBrew]

Your red stuff could be either cyano or spirulina. They can look the same in the tank. @twilliard developed instructions for a simple test using hydrogen peroxide to tell the difference here:

https://www.reef2reef.com/threads/positive-identification-of-cyanobacteria.253287/

The treatments for cyano and spirulina are different. @twilliard and @jason2459 have both done a lot of work on this topic and have several threads on R2R that have helped me out.