T5 Fixture size for 120g tank?

[Rowdie]

I've decided to get a dimmable ATI sunpower for my 120g (48''x24''x24'') build, but I'm torn on what size to get (6x39w/6x54w). Also is the dimmable ATI sunpower worth the extra money over the normal sunpower?

I'm planning on doing mostly SPS and right now I think I'm leaning towards a 6x39w fixture as this would allow me to keep SPS for the center 3 feet of the tank and then put some LPS/softies on edges of the tank.

I plan on accenting with reefbrites or some other sort of led at some point as well to try and add a little pop/shimmer to the tank.

TL;DR What's a better size T5 fixture for a 120g (6x39w/6x54w) tank and is the ATI dimmable fixture worth the extra cost?

[Peter Eichler]

I'd suggest 8x54 and not to worry about it being dimmable. 6x54 would really be best for a tank that's only 18" front to back.

[Rowdie]

I'd suggest 8x54 and not to worry about it being dimmable. 6x54 would really be best for a tank that's only 18" front to back.

If I do go 8x54w what sort of lighting schedule would you suggest? I'm coming from leds on nano tanks.

[sabo]

Dunno, I've got a hybrid 4x39 and with the extra 2 bulbs I reckon the light would be wide enough, then again, 8 would be better. ☺ Definitely go 54w tho, I have slight shading at the ends of my tank same size.

[Chris Lakies]

8x54 is what i use. My lighting schedule is:

2 x Blue plus on at 1pm
The rest of the bulbs come on at 2pm go off at 10pm
2 x blue plus off at 11pm

Things seem to like this schedule!