We have 4 spots of hair algae growing in our 150g. One is on this giant tunicate. It looks like a beard. Sorry for the poor pictures but my camera just does not do justice to this (either that or I am just a rotten photographer.)
The other just showed up yesterday on this bivalve.
Again, just a little beard. The other two areas are at the back of the tank behind a rock and in between two rocks in the middle of the tank. None of the rocks are small enough to remove from the tank so I have just been plucking it. We have lots of macro both in the fuge and in the main tank so I'm hoping that the good macro will outcompete the hair algae and it will not get any worse.