Red spots on rock

[stharper2923]

Can someone tell me what these red spots on my rock are? Coralline? Dinos? Cyano? I scrubbed gently with toothbrush and it did not come off.

 

[ISpeakForTheSeas]

Can someone tell me what these red spots on my rock are? Coralline? Dinos? Cyano? I scrubbed gently with toothbrush and it did not come off.

It looks like coralline to me, but this is not my area of expertise at this point - so hopefully someone who knows for sure can chime in here. That said, I see what seems to be some bubble algae mixed in there on the left side of the rock that most people would recommend removing before it spreads too badly.

 

[muzikalmatt]

I'm not sure if it's the same, but it looks very similar to the dark crimson algae I have growing in my 40 gallon. You can see it on the back wall of my tank in the picture below. It is a disinctly different color from the corraline growing next to it. I find it to be harmless and usually it just grows on the surface of the rock and walls of the tank. Occasionally though it grows outward into the large piece you see in this picture. I've had this kind of algae in my tank since nearly the beginning (I believe it came from my LFS), but only recently did it grow outward into this larger piece. I'm still trying to identify the species though.

 

[KQuillan]

https://www.reef2reef.com/threads/cyano-bacteria.958367/#post-10935129
Look at this thread. :)

 

[shakacuz]

if it does not scrape off, i believe it to be coralline algae. the two posts above could perhaps be it as well, but the red blotches i have in my tank i feel very confident is CA, and it looks just like the picture you’ve provided.