Adding a reflector will increase the light levels getting into the water.
As it is now, about half your light is being wasted.

Steve
wrote in message
I have a home made hood with Ice Cap 660 ballast 3 110w actinic white
bulbs and 1 110w super actinic bulbs over a 75 gal tank. I dont have
a reflector built into the hood. Is that really necessary? Also, I
use the glass canopy the tank came with. Is that a good idea? Does
the glass interfere with the intensity of the bulbs? Corals just dont
seem to grow like I want them to. (soft and hard) no sps
Any thoughts