Diatoms or cianobacteria?

[Jorge Frazoa]

Good evening everyone

I've been struggling for 4 weeks with a dinos outbreak. However, I managed to solve the dinos by starting to dose Po4 and with dinoX, from the marin fauna. However, the rocks and sand get a reddish brown "dust", can anyone help me to understand if it's cyanobacteria or diatoms?

Thanks

 

[blaxsun]

Looks like cyano.

 

[Cali Reef Life]

I agree Cyanobacteria