well...my tank has been set up for about 2 and 1/2 months....and there was a major outburst of this brown stuff (diatom i believe) and it kinda went away...but i want it all gone....at first it kinda gave a bit of color to my rocks...but now that i look at it...its really kinda just dirty looking...is this stuff bad?? how do i get rid of it?? and yes it is on everything rocks, sand and glass