Dinos, Diatoms or Cyano?

[Intheflesh]

Hi all. Long time lurker, first time poster. I have been in the reef hobby for about 14 years now. I recently transferred coral, fish and live rock from a 80 gallon shallow to a RSR350. I did not reuse the sand. I went bare bottom for a little bit, and all was fine. I added about 40 lbs of fine sand from petco (forget exactly which brand), and within a few weeks this nasty stuff showed up:

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• Intheflesh
• Feb 2, 2018

25398716_10215504835117882_3233224537241828967_n

• Intheflesh
• Feb 2, 2018

So the red on the rocks, I'm fairly certain is cyano. These are old pics, and the cyano on the rocks is no longer. But the brown stuff on the sand bed remains. Its growing on the sand and glass, and doesn't appear to be growing on the rocks. Not sure what this is. I was running on the assumption that is Diatoms because it does not appear stringy or snotty. I just added sand, so maybe diatoms were feeding on the silicates in the sand? But it has been months, surely the silicate source would have been exhausted by now?

Another possible source of silicates is my RO/DI. I just changed my DI resin a few weeks ago. Perhaps depleted DI resin was allowing silicates into my top off water?

I do run GFO and carbon in a reactor, and I change about once every 4 weeks. I do not do any carbon dosing. My skimmer is an Omega 150 that skims on the wet side. As far as phosphates and nitrates go... I'm, honestly not sure. I'll take a reading when I get home tonight.

So what do you guys think it is? I'm fairly certain it isn't dinos. I'm leaning towards Cyano or Diatoms.

 

[Kremis]

Cyano, it is pretty thick enough to be it and you mentioned you already had it. looks exactly like some of what I would get on my 180. I chemicleaned and it went away. Diatoms remained, so I had a little bit of both but it never went away so I added a sand goby to fix the problem.
You can use chemiclean to treat. its safe

 

[Intheflesh]

Thanks for the response. I posted this on my local reef group FB page, and someone else suggested cyano, but I was thrown off by the color. I also forgot to mention that this stuff seems to 'go away' when the lights are off. And if I vacuum it up, it comes right back the next day. I suppose the best way to tell what this stuff is would be to get a microscope lol.

 

[Kremis]

Thanks for the response. I posted this on my local reef group FB page, and someone else suggested cyano, but I was thrown off by the color. I also forgot to mention that this stuff seems to 'go away' when the lights are off. And if I vacuum it up, it comes right back the next day. I suppose the best way to tell what this stuff is would be to get a microscope lol.

Yes I had that happen to me too. I have had neon green cyano, the usual red, and brown. brown/red is most common