Help to ID this red stuff that's on the rock

[Carrera75]

This red stuff has been on a piece of liverock since I set up the tank. It didn't spread for a while but I have noticed that it has started to spread slowly on to the other rock. I would like to know what this is so I can try to kill it/get rid of it. Is it some type of algae? Any advice on how to fix this problem is welcome. Thanks in advance ......





cheers