Red slime?

[Nem0]

Tank is 3 months old. Noticed this red stuff pop up early this week/last weekend. In multiple places of the tank, not bad at all but want to get it under control early if it is red slime or cyno. Let me know what yall think it is.

 

[Brew12]

There isn't enough there for me to say. If you take a brush to it, will it come off easily? If it doesn't brush off it could be coralline.