What's the dust stuff on my live rock?

[gemini9]

In my tank I have 2 or 3 pounds of live rock and 20 pounds or so of dry rock that's been cycling for about a month. Maybe more. The 3 pounds of live rock I bought at LFS has dust and dirt particles on it. I moved around some rock today. The live rock was over in the corner of the tank and I wanted to bring it out a little more to maybe filter out these 160ppm nitrates and better cycle the tank. When I moved the live rock, all this dust dirt and debris fumbled off of it and I'm wondering what it is. I dont' have any fish yet. No cuc either. So this dust and debris that came off the live rock... is this beneficial bacteria? Or is is all bad stuff? Algae? It's not on my dry rock, only on the 2 pounds of live rock I got. Is it die off? Did I kill my live rock when I was trying to cycle this tank? :squigglemouth:

 

[Reefing Madness]

probably just the corrner where all the dust and debre dropped after the tank settled in.

 

[fishroomlady]

sounds like detritus - settling from things going on in the tank. Sounds like you may need some more flow throughout the tank.

 

[gemini9]

No fish yet. I have a circulation pump in there so I have decent flow. Actually I wonder if that debri could be resulting in my nitrate problem. If its not beneficial bacteria im gonna siphon it