T8 and T12 are out. Not strong enuff.
A 2-4 bulb T5 HO
would provide enough light for most corals.
However, if you want to build, LED
is the way to go. There are lots of videos of people building their own fixtures.
I would go with a 3 channel controller (Blues, whites, green/red). Use Cree LEDs in 3 and 5 watt, high efficiency outputs. You could use simple power supplys as your controllers (hooked to timer switches) or more costly programmable controllers. Get enough LEDs that you only need to run them at 66% max output at full to prolong the life of the LEDs and controllers.
240 watts total output is more than enough, so design with 330-360 watts in mind.
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