Is it coralline algae or not?

[fhd]

Hi all, after 40 days I am start to see some purple spots on the dead rock as showen in these pictures below, what do u think it is, I am lucky I am starting to get coralline algae or not?
My tank is 200 gallon
Nitrites 0
Nitrate 5.0
Amonia 0
Ph 8.2
slinalty 1.023
Phosphate 0
Calcium between 350 420
No coral
200 lbs dead and diy live rock
15 lbs live rock

 

[Reefing Madness]

Yup, looking like Coralline Algae.

 

[Dalmatia]

Yup, looking like Coralline Algae.

I agree 110%

 

[fhd]

But somebody told me it is red slim algae or kind of bacteria

 

[Reefing Madness]

Not from my seat. Looks right on from here.

 

[Dalmatia]

Plus, cyano (slime algae) will spread like crazy. In a day or 2 the whole tank could be overrun by it. You don't have red slime

 

[fhd]

Plus, cyano (slime algae) will spread like crazy. In a day or 2 the whole tank could be overrun by it. You don't have red slime

I turn my light of but some off rock I try to clean it from these spots and I can clean it. any idea?

 

[Reefing Madness]

If you rable to just wave it off with your hand, its cyano, if you have to scrape it with your nail, its coralline.

 

[preston469]

+1 on caraline

 

[fhd]

Because the spots only on the top of the rock wich is near live rock the other rock doesn't have any of this spot

 

[Dalmatia]

Plus, cyano (slime algae) will spread like crazy. In a day or 2 the whole tank could be overrun by it. You don't have red slime

Posted this in the wrong thread,, sorry,,, just noticed. It's not cyano