New reef tank with burnt looking rock, algae???

[brandon999]

Tank is about a week old. Used bacteria live sea water, and a buddy with a 300 gal gave me live rock that’s been in his sump for 8 years filled with copapods. Seeing this algae that almost looks like burnt rock. Is this normal?

 

[shakacuz]

totally normal and part of a reef ecosystem. what you likely see is diatoms, and they come and go as your tank matures.

 

[DJC]

Agreed perfectly normal
My tank is 6 months old now got an amazing piece of established live rock for LFS with lots of purple all over it after placing it in my tank it turned to the above picture however now it’s super flourishing again

 

[UGASealDawg]

Agree also - totally normal. It will come and go in my experience. Nothing to worry over for sure. If you don't particularly like, then find a couple fish that will graze on it to keep it at bay.