Okay now, I'm really curious about this blue bag technique. Did you install the blue bag to reduce intensity of the light, or to convert the light to become bluer (by filtering out the yellow)?
Not too long ago, I replaced the incondecent bulb on my 5.5g with a compact florescent that I bought from Home Depot for $8. The new bulb is much brigther but it's rated 3000K, and come to think of it, I do get more algae now. Should I be doing the blue bag thing? What about the heat from the bulb and the possibility of burning the bag? won't the blue bag become brown bag in time?... :?