Hi, this is my first reef tank. The tank has been cycling since 30/10/16. I got it from a guy whom had lost interest and the tank was filthy with ugly peices of live rock in it. It already had 2 clown fish and a Pijama fish in it. I slowly changed out the old live rock and coral sand with new stuff. Everything has been fine until i noticed this green algae after rearranging my liverock. Its a 4ft tank and I am running a 2ft sump with filter sock, skimmer and bio balls. No corals or anything in the tank yet. Is this algae good or bad? Its only on that one rock really. Also Some of the live rock i put in still had dying matter on it as it came fresh from the barrier reef. Some of the coraline that did exist seems to be breaking down. Any help would be appreciated. Thanks
