Looks like cyano to me. If you can scrub it off with a brush then its cyano, if not then its something else. Heres a link to a thread on cyano Click here
Heres the picture so other people could see it without going to the link.  _________ 90 gallon tank with center overflows, 44 gallon custom sump/fuge, Tek T5 retrofit 4x54 bulbs, Reef Octopus nw200 protein skimmer, Iwaki WMD40RLXT return pump (changed to panworld 100pxx),Knop c ca reactor, PA light house controller.
Click: Real-Time Stats 
^^ Testing it out! Ill add more param.. later. |