Red Purple Rocks are they healthy

[Lisa Cain]

Dear all, I took my eyes off of my tank due to sickness in my family. I am now trying to bring it back to a healthy state. The waster is okay, however, there is a red purple type algae. It is not slimy. Does anyone recognize it? I want to start putting anemone back in and corals but I am wondering about the rocks and the algae.

 

[smitten with ocean life]

its hard to tell what you mean in the pics. is it coraline?