Still looking for a positive ID

[Ippyroy]

I am still trying to get a positive ID. Here is a better picture. This stuff will come off easily with a turkey baster. I have plenty of flow. An MP10 at half power inches away.

 

[Ranjib]

if its not fixated on the substrate/rock then I'll incline towards bacterial growth. Most algae should fix firmly on the rock

 

[Ippyroy]

if its not fixated on the substrate/rock then I'll incline towards bacterial growth. Most algae should fix firmly on the rock

That’s what I thought. I think it might be a form of cyano. Calothrix maybe?