lighting for new tank

[Jim Barry]

I am building an inwall tank early in the new year and I am trying to determine the proper amount of lighting. It will have mainly SPS and the lights will be about 8" from the tank surface. The tank will be covered with a removable top made of Starfire glass (or acrylic).

The tank will be 5'x 24" height x 30" front to back.

I am currently running 2 - 250w, 10000k metal halides and 2 - 40w actinics on a 4' 120 gallon tank and I am concerned I won't have enough lighting for a 5' tank.

I am considering supplementing what I have now by adding one 400w, 10000k in between the 2- 250's. It will also be in an enclosed canopy with 2 - 4" fans. I am concerned about the heat in the canopy and I may add a chiller to control the water temp, but I am concerned about the heat buildup in a totally enclosed canopy venting with only 2 small fans.

Will the lighting setup of 2-250's and one 400w give me uneven lighting or can I get away with using 2 - 250's on a 5' tank?

Your thoughts on the lighting and heat issues would be appreciated.

Thanks,

Jim