Is this some type of algae or diatom?

[WnYreefer]

Would anyone be able to identify what this is? My nitrates are about 20 and last i check my phosphates are at 0 or around there. I am using a TLF reactor with GFO. Is it a diatom or algae? I do need to change my light, i was thinking that maybe the reason why.

Thanks for the help!

 

[Electrobes]

Are you talking about that brown stuff in the middle of the pics? Kinda looks like what coral death would on a skeleton. Usually it just passes in a week or so. Do you have more of this stuff in your tank?

 

[WnYreefer]

Yeah its the brown stuff. I'll try to get a better pic when i get home. It is spotty through my tank not too much just trying to figure out what it is and how to solve it. It is also on parts here and there on rock and occasionally on a powerhead. That frag fell on another coral and it turned white, there still is part of the coral on the bottom. On the top however it is turning brown.

 

[WnYreefer]

Here is hopefully a bette pick.