"Algae" ID.......anyone??

[JM Houchin]

I've been battling an unknown "algae" for sometime now and would love some help identifying what it is. My LSF is unable to help. I have a mature 90gal mixed system (7yrs) with tangs, clowns, wrasse, chromis (6) total fish.

There has been no changes in all the major water parameters, lights, flow, maintenance routine, none since I started it. It showed up one day and it's been a battle ever since.

I describe it this way:

~it starts as a single speck on the sand bed, rock, and even the coral
~it then multiples and starts to spread (like overnight)
~left alone it forms a "carpet" covering the surface completely
~not sure of color looks purple??
Please forgive the pic quality

top pic of the whole tank (w/whites turned up)

visible in the sand bed and at the base of the rocks

bottom pic is my pipe coral colony and the dots are it and how it starts

Thanks!

 

[SaltySam09]

Could you get a closer photo? Hard to tell from that distance.

 

[JM Houchin]

Hopefully these are better.

Whatever it is it's driving me crazy
You can see how it starts when you look at the coralline, individual tiny grains like sugar. It spreads quickly
It does brush off the rocks easily. Have not found a way to remove it from the sand.
Thanks

 

[SaltySam09]

Hopefully these are better.

Whatever it is it's driving me crazy
You can see how it starts when you look at the coralline, individual tiny grains like sugar. It spreads quickly
It does brush off the rocks easily. Have not found a way to remove it from the sand.
Thanks

Sorry for the late response, it looks like Cyanobacteria