Is this a type of coralline?

[exnisstech]

I started this tank 10 months ago using dry rock, bottled bac and a container of seeded rock rubble. I have been dosing bacto balance and zeobak for 6 months or so and to me the tank is looking very good. I've had very little nuisance algae or bacteria. Acros are encrusting and this stuff does not appear to be growing on the coral. This is my first dry rock start up and I do not have this in my other 2 tanks so I'm more curious than worried. It does not blow off, is smooth but not slimy and I can not scrape it off with my fingernail. Colors in the images are pretty close to the actual colors. I have some coralline on the glass and pumps but it's the typical light purple that I get in all the other tanks. TIA
FTS
A couple closer shots

 

[JGT]

Yes, maroon coralline. If it doesn’t blow off which you said it doesn’t then that’s what you’ve got. I’ve got lots of it in my tank. Nice contrast with the pink, purple and green.

 

[blecki]

Is it slimy? Does it blow off the rock if you take a turkey baster to it? No? Then don't worry about it.

¯\_(ツ)_/¯​

 

[shakacuz]

i also have this in small areas of my tank. doesn’t grow as fast as the normal pink/purple

 

[exnisstech]

Thanks folks. I'll admit I was getting a little concerned Mostly because I don't have the same stuff in my other two tanks. I assume probably because they were started with live rock which was most likely already populated with other life. I do kind of like to looks of it.
Maybe I'll snag a small rock with some on it and put it in my other tank that is struggling with algae right now. Diversity can't hurt.