Are you feeding that tank? IF so, what? Sorry, but I can't remember if you're using ro/di or not there...
-check bulbs age (they gradually shift to the nusiance algae loving spectrum of red)
-reduce any po4 additions (food, tap water, non-ro/di soaked carbon, some additives, etc.); soak all foods in ro/di prior to feeding
-remove po4 (polyfilter, phosban, rowaphos, siphoning cyno out, siphon diterus, clean skimmer, etc.)
-check nitrAte levels
I wish I had room for a phosban reactor under my tank; I would sure set one up!
-check bulbs age (they gradually shift to the nusiance algae loving spectrum of red)
-reduce any po4 additions (food, tap water, non-ro/di soaked carbon, some additives, etc.); soak all foods in ro/di prior to feeding
-remove po4 (polyfilter, phosban, rowaphos, siphoning cyno out, siphon diterus, clean skimmer, etc.)
-check nitrAte levels
I wish I had room for a phosban reactor under my tank; I would sure set one up!