Jan 20, 2014 #1 S shadowbrk Aquarium Advice Apprentice Joined Dec 7, 2012 Messages 26 What is this red thing growing all over the rocks?
Jan 20, 2014 #2 Ej_b1996 Aquarium Advice Activist Joined Nov 23, 2012 Messages 159 Looks kinda like coralline algae