While sitting at a computer Christopher wrote:
In my 125g I have 6 20 watt bulbs, 2 are actinic 03 and four are
powerglow. I was wondering if anyone had any ideas about turning on
(via a timer) the two blue actinic lights say 30 minutes before you
turn on all the lights and leave them on for 30 minutes after the
powerglo's turn off. This could simulate sunrise/sunset. Anyone
have any experience? Did you use actinic blue or another color? I
woulnd't be adverse to putting in a fourth set of lights for the
purpose of the sunrise/sunset part. What is a good color? I like
the blue because its not too bright even though its 40W over a 125g,
the equivalent wattage of powerglo's makes it bright (not a dim
sunrise/sunset). Should I step down to a smaller bulb for this and
put in say a 10W ballast in each light hood?

Thanks

http://www.thekrib.com/Lights/sunset.html

never tried it but it sounds really good, if you can get the bulbs!

Stu