Updating lighting over a 120G reef

[nashlake]

I am building a new hood with updated lighting for my 120 gal mixed reef tank. Mostly SPS with clams with a few LPS. Tank is 48" x 24" x24"

I am currently using a hood originally made to fit a 90 (18" wide) gal tank made for VHO and later converted to (2) 400 W MH with spider reflectors and Lumatek electronic ballasts. I am currently using 14K mogul end bulbs. The original hood doesn't fit the tank and I am going to make a new enclosure for the lighting.

On my new system I am planning on using 2 Hamilton Cayman Sun - 400 Watt HQI Reflectors and either (1) or (2) Hamilton Aruba Sun T5 Retrofit fixtures. The Hamilton T5 fixtures each hold (2) bulbs.
I will probably stick with 14K bulbs for the MH and add actinic or blue-plus bulbs with the T5

The MH reflectors are 12" wide and the T5 fixtures are 5" (total of 10"

The total width of all fixtures is 22" on a 24" wide tank.

I have plenty of light with the (2) 400W MH and it will probably increase with the improved reflectors but want to add the actinic with the T5 and I'm not sure if (2) T5 bulbs would be enough.

Am I leaving enough room between fixtures or should I use only one T5 fixture?

I know the hood will be full and need to address the heating issues. My current set up has heat issues, and the new enclosure will have an open top.


Any suggestions or recommendations would be appreciated.

 

[dz6t]

I think 400w MH is over killed for a 120g. The heat they generate INSIDE a canopy can be a big issue in summer.
I would use two Radium 250w 20K SE bulbs without any actinic t5.

 

[nashlake]

I tried the radium bulbs and they looked good but not really much difference in color than the Hamilton 1400K bulbs I am running now.
I was hoping to add the T5s to get the blue color I had with the VHO set up.
The Lumatek are adjustable to can run either 250 or 400W bulbs so I can cut back with the MH if the T5s add too much light or heat.
The plan for the canopy is more of a light shield with an open top. The tank is in the living room and I need to keep the light directed into the tank or up.