t5's

I have a waterbox frag, 48x24x16. I have a Kessil AP9X lighting the tank but I want to try out the T5 hybrid. I’ve never had T5’s before and I’m not sure how to go about it. Do I get a 48 inch fixture or will a 36 inch be enough? Can I use it with the Kessil AP9X? What brand and fixture should I...

FS: 24" aquatic life hybird t5. new one month ran bulbs. 2x coral + and 2x Blue +. comes with hanging kit and kessil and other square light bracket. issues. $200 shipped with fixture and bulbs.