I just got a t5 fixture and wanted to know what bulbs would be best for a reef tank. The fixture has 4 X 54W and I currently have 2 12,000K and 2 Actinic Blue bulbs.
Turn the whites on about an hour or so after the blues turn on in the morning, and turn them off about an hour or so before the blues turn off at night. The times aren't that important but shoot for about ~10ish hours total. You can leave the LEDs on all the time if you wanted.