With the ATI T5 lamps, the blue+, aquablue, and coral plus all have good PAR (light intensity) so any of those bulbs are good for growth. Which you run is largely a matter of what color of light you prefer to look at. Actinic lamps have lower PAR, so they can add a nice "pop" to the look of the corals, but that's at the expense of some intensity.
Blue+ = very blue looking light (actually a fairly wide spectrum, but the blue is extra strong so it's what the eye sees the most)
Aquablue = Looks mostly white (A similar wide spectrum but not as heavy in the blue so it looks much more white and less blue to the eye)
Coral plus = similar to the aquablue but with a hint more purple.
Actinic = Very limited band of blue/vilot light (Not full spectrum at all, only the blue/violet range with none of the red/yellow/green. Very blue looking to the eye, but overall very weak in intensity)
Personally I would go with not more than half Blue+ because I like a little more of a white look. IIRC I'm currently running 2 of each in a 6 lamp fixture (but I'd need to double check that since I haven't thought about bulbs for the better part of a year)
