My tank is about 4 weeks old 90gallon w/ 100lbs of live rock. It fully cycled about 2 weeks ago, now Im getting some bright green algae on my rocks and sand. Is this normal and do I need to do anything? The tank already went thru the brown algae cycle and that seems to of ended. Also what is the little green algae that looks like a little feather or plant branch attached to my glass?