Algae or Bacteria????

[rc1626]

Hi Folks,
I've got a 120 gallon reef that was started back at the end of March. Noticed this stuff growing on the rock and the sand mostly where lighting is the highest. I first noticed it about a week ago (could have been there longer). Not sure if it's a form of algae (Dinos) or bacteria (form of cyano)? Looking for help identifying and hopefully controlling.
Tank Parameters are:
Alk ~ 8.0dkh
Ca ~ 405
Mg ~ 1300
PO4 ~ 0.01
NO3 ~ Undetectable using Salifert

Haven't run Ammonia or nitrite test since tank finished cycling.

Lighting has been 8 ATI T5 bulbs run using Hamilton Aruba Sun Fixtures. All new in March. Run for 8hrs./day.
3 Blue +
3 Coral +
1 Aquablue Special
1 Purple Plus

Current Livestock list is:
1 Rock Beauty Angel
1 Flame Angel
1 Potters Angel
2 Bangai Cardinals
1 Talbots damsel
1 Blue Chromis
Pair of Ocellaris Clowns
20 Banded Trochus Snails

Algae/bacteria is really light brown to almost white in color. It is mat-like and stringy. There are some air bubbles trapped in it.

Pictures attached.
Thanks in advance for any help.

 

[rc1626]

Just a little more info that may be of help. Rock is BRS reef saver. It was used in my last setup. It was bleached and cleaned before being reused. I added a small piece of rock from another tank to help with cycle and to introduce coralline algae. I'm assuming it must have come in on that rock.
My Ph fluctuates between 8.0 and 8.2 Night/day.

 

[vlangel]

I doubt that is bacteria, and it looks more like algae to me. Still its hard to tell from the pics.

If I were you I would cut down on the lights a bit and maybe add beneficial bacteria like Seachem Stability weekly to boost good bacteria.

 

[rc1626]

Thanks vlanfel. After doing some research it does look a little like dinos but not positive. Things I'm considering are lights out for a period of time, adding some microfauna, adding to my CUC and adding gfo.
Anyone have any other thoughts?
Thanks.