Question about t5 spread!

[alonso24k]

I currently have 2 kessil a160we lights on my 29 gal but I'm upgrading to a Red Sea reefer 250 and instead of adding another kessil I want to add an Ati 4 bulb t5. My question is, will a 24" fixture have enough spread to light the extra 6" on each side of the 36" tank or should I just go with a 36" fixture and put the kessils in front?

 

[Aznxgqboyx]

Maybe 2 36" t5 bulb on each side with tbe 2 kessils in the middle like this

 

[Salty1962]

I would go with the 36" to give you the best coverage.