GE makes a dimming compact fluorescent light bulb (called the Energy Smart Dimming Spirals) that is specially designed for use with dimming switches. The bulbs runs about 15-23wats and around (some bulbs) 4100k-2500k. The problem I'm looking over is how can u get these to work for the fish tank? In drop lights i can under stand, but if you have a canopy you would have to make some kinda of sideways socket. With reflectors. This light would replace the LED i see people using for Moonlighting... It would be cheaper/ less usage on energy with the LED but don't u think the DCF will give the tank a hold different look? What do you think. I"m playing around with my dimmer in my room... the moon doesn't always give a blue look to the water.... I think this will look awesome inside a tank.