Well, I don't have a refugium, I do have a 60g tank with a flow of 920 gph provided by 4 Zoomed Power Sweep Power heads (2x 190gph + 2x 270gph). I also run a H.O.T. Skimmer rated for a 90g tank, I run Phosguard by Seachem in a micron bag on the bubble catcher for the skimmer. I also run my lights for 12 hours with a 3 hour break in the middle of the cycle. My aquarium get a little bit of indirect sunlight due to some windows that are near. My lights are Current's Nova Extreme T5HO Setup which are 2x54w True Actinic T5HO, 2x54w 10,000k Daylight T5HO, and 4x L.E.D. Moon Lights.

Don't know what else might help you help me.

p.s. I also have a bit of a problem with my skimmer's bubble catcher allowing some micro bubbles into the tank, I don't think it is related but who knows at this point.