Looks like cyano to me, could be dinos to. Either way vacuum it of the sand and rock, you can useaturky baster to get it loose if need be. If it starts spreading like crazy you can always use chemi clean, I have used it 2 times fo cyano and had no negative effects from it, just follow the directions carefully. As your tank matures it will go through several stages of the uglies.
I have clean all of the nesty stuff and in about 3 days is all over my rock again. Any advice how can I get this under control? And maybe tell me what it's?
That’s a young tank, it’s probably still going through it’s cycle. I wouldn’t try and use any additives just yet. Let it do it’s thing and keep up on Water changes.
It really looks like the cyano i got a few times when my tank was younger, but mine would die back and almost disappear off m sand bed at night and within a hours of my lights being on would be back in full force, if not worse. At the beginning of the 2 outbreaks i was able to keep it at bay by blasting the sand and rock with a turkey baster evey day and vacuuming the sand and rock every week. Both times it would slowly get a little worse day bu day. I was very reluctant to use anything but eventually used chemi clean. It truly does work wonders and did not hurt anything. The owners of one of the LFS i go to convinced me to try the chemi clean, explained it to me as cyano is not algae it is bacteria, treat it directly and it will go away. I have seen zero spots since the second time I used it. Just my experience.