It looks like it could by cyano, but it could also be that algae that looks like pink cotton candy too. If it's the latter then you want to get rid of it asap. Don't pick it off in the tank, do it in a bowl of water outside of it. Apparently the stuff is really invasive, more so than most other algae. I had some show up on an acro frag plug a while back. I removed the plug/frag and put it in a bowl of tank water, picked the algae off and tossed it in the trash as I went. I then dipped/swished it in another bowl of tank water and returned it to the tank. I haven't had any ill effects from that method. Apparently turbo snails will much on the stuff too, so there's another fail-safe