I have made several posts(in other parts of the forums, so forgive me..i never saw this particular sub-forum). My tank is about to hit the two month mark (up and running). I only have a few piece of coral..some acros, wellsys, chalice, lepto, hammer and torches. I have about a dozen fish, all small (under 3", except two), they were carry overs from my previous tank. My current setup consists of 200 gallons plus a 50 gallon sump with small fuge. I have three G3 Radions, two Mp40's on 100%, a 1200 GPH return pump on 100% (adjustable), 100 pounds of cari-sea sand, 120 of cycled dry rock, Bubble Magnus Curve 9 skimmer, a phosban reactor with ROWA and chemipure Elite in each filter sock. I am constantly getting brown slime type substance on the sand and rock. It grows back immeidtaley after I clean it and sometimes gets long and stringy with bubbles. I have gone back and fourth with between cyano and dino's, although 95% of all people I ask, seem to think it's cyano. Phosphates are .07 (checked with a hanna) and nitrates are undetectable with red sea kits. What is the best approach to get rid of this stuff?