T5 bulbs
 

I have a T5, 4x54w fixture and need new bulbs. What would be my best combination of bulbs for this fixture.

It depends on your taste in colour. In my four bulb I use KZ's 1 of each, fiji purple, superblue, coral light (10k), and new gen (14k).

2 x uri 10k, 2 x 454nm or indigo sun

I'm currently using all KZs - 2 x Superblue, 1 x Coral Light (10k) and 1 x New Gen (14K). Two of the bulbs are on a separate timer so at dusk/dawn I use the Superblue and New Gen and daylight the other superblue and the Coral Light. I get a nice blue (but not Avatar-ish blue/flurescent) for dusk/dawn and crisp bright white for the daylight.

I also use this setup, it's always a mix of preference and what you're attempting to achieve. The mix of one of each type gives a nice broad spectrum.

I am running 1 pure actinic(geisemsn), 1 ATI purple plus, 1 ati blue plus and 1 KZ super blue. More of a blue look.