Is this Coralline or something else?

[downonthereef]

As the title says!

Tiegs

 

[Sleeping Giant]

Looks like cyano, try blowing it off

 

[BostonReefer300]

I can't quite tell from the video. Try scratching it with your fingernail. If it's coraline, it'll almost be like trying to scrape paint off a wall.

 

[downonthereef]

Looks like cyano, try blowing it off

Blowing it did nothing,. feels like scratching paint so I'm assuming it's coralline as per the @BostonReefer300's reply