Seriously, correct me if I am wrong please, but wouldn't you want to use something w/ sides that reflect light back to the inside of the fuge, like a white tub instead of a dark blue, green, or black one? These dark colors absorb a lot of the available light. This takes light away from the growth in the refugium. Isn't this a bad thing? I'm not exactly well educated on refugiums, but I DO know a little about how light is used by everything. I just think using something lighter in color would make the fuge more effective. If I am blowing this whole light thing out of proportion, let me know. I'm curious.