So they say its cyano?

there is also a red rhodypta that looks and feels like red velvet, its definitely benificial but not coraline. it is not the health indicator that coraline is since its a vegitative macro- algea but good all the same

 

cyno will be everywhere, not just your rocks. My coraline looks just like that. I have a few rocks that are all deep red like that.

 

There's many colors

HI,
I ve seen pink, red, green, dk green, white, orange. Its all alittle different, I shop around the LPS and I see a pink rock I buy it to seed my tank with pink.
I have a lot of green , I thought it was a bad algae but it is very hard to scrape off the glass or rocks and its growing in layer like coraline on in takes and over flows.
Doug

 

That's what it looks like to me.

 

Coraline is Rhodophyta.

Phylum Rhodophycota (Red seaweeds)
Class Rhodophyceae

the geniculate (articulated) corallines; Geniculate corallines are branching, tree-like plants which are attached to the substratum by crustose or calcified, root-like holdfasts. The plants are made flexible by having non-calcified sections (genicula) separating longer calcified sections intergenicula).


the non-geniculate (non-articulated) corallines; Nongeniculate corallines range from a few micrometres to several centimetres thick crusts. They are often very slow growing, and may occur on rock, coral skeletons, shells, other algae or seagrasses. Crusts may be thin and leafy to thick and strongly adherent. Some are parasitic or partly endophytic on other corallines. Many coralline crusts produce knobby protuberances ranging from a millimetre to several centimetres high. Some are free-living as rhodoliths (rounded, free-living specimens). There are over 1600 described species of nongeniculate coralline algae.