i have a 55 gallon long tank with a whiper 60 filter and a seaclone 150 protien skimmer. I have had it setup and running for about 3 months with no problems. i have 100 lbs of dead coral rock, 2 firefish, 4 convict gobies, 2 citron clown gobies, a yellow tang, 3 green chromis, a emrald crab and a coral band shrimp. i noticed some brown algea and cleaned it off the botom and now it seems like i can't get rid of it, it seems like its powdery cause i can get most of it off the rock by swishing the water around. i also have a 52 gallon bow front with a skitler 400 filter and a ventura 20 protien skimmer and it is starting to get the same algea too. How do i get rid of it??