Keep It cool!
I had to cool the hood, I made a mistake, of having the Halides about 4" from the water. I use 2 quite cooling fans to cool the lighting. The fan on the right pulls air in, and the left exhausts the hot air. Both of these fans are on there own channel that is controlled by my Neptune. I program than fans with the the light changes (i.e. sunrise, sunset), and temperate changes.