So I got this rock almost a year back with a coral on it, but it detached when it was places in the tank. Nothing was on it except the coral, but in the last two months, I notices this weird stuff growing on the corals. it looks like this and I don't know what it is, can someone tell me (btw, if someone can also tell me what this coral on it is as well, that would be awesome)? I can't get a better picture because I had to crop this just to upload it.