i want the bi light 2 because i like the idea of having the two seperate cords and not having to unscrew a lightbulb when i want to switch from day to night. (also, am i right about this too? that you have to unscrew one of the lightbulbs when you want to go from the dayglo to the nightglo if you are using just the bi light system?) this is all new to me.
And do I NEED to get a 30 inch long fixture just because my tank is 30 inches long or is it ok to go for the 24 inch? will it make a difference in the amount of heat in the tank?
right now i have only a flourescent light but that does nothing for the heating. but i plan on keeping it on top of the tank with the ESU fixture (sorta like my own combo light ...)
Can someone help?

Also, where did you buy your ESU fixture and bulbs? I'm looking to buy online.