Unknown Algae Growth

[Time to Reef]

I have noticed a small amount of dark red algae on some of my live rock. It is very brittle and can be picked off easily with a hard instrument. I have very good growth of purple coralline algae happening on the live rock. I do have a patch of cyano on the bottom of the tank but it does not seem to be spreading as I'm siphoning it out once a week with the water changes. Is the hard red algae/growth on the rocks detrimental and what exactly is it?

[Blown 346]

Sounds like red corraline algae. You can get green,red,pink,purple.

[steven_dean17]

If it looks like red velvet, its good, the green should be ok too. They both sound like corraline.