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

[andsoitgoes]

ah crap - That looks like cyano or red hair algae... I'm not sure which... What I had started off as a small chunk on a rock, noticed it had a lot of air bubbles on it, figured out it was cyano.

It might not be spreading now, but it could soon - you're great at water changes, so maybe slowing down the feeding? When did you start to see it spread, did you add anything else in the tank around when that happened?