24g tank

Tank is about 3 months old now, have had good results with everything except the Pocillopora, it appears to be bleaching, probably not enough light. GSP and Xenia have been growing like crazy. Still have problems with the brown slime growing on the substrate, changing 5g/week with RO. I'm not running a skimmer but have one on order, I'm hoping that removing some more DOM will help get rid of the slime algea, cyanobacteria, or whatever it is.