My 120g came with two single bulb 36 inch fixtures. I bought the conversion kit for AH supply so now each strip has a 96 watt cfl in it. I mounted the ballast on the outside back of the lights to help reduce the heat. The first night I sat the lights directly on top of my glass hoods and within 1/2 hour one piece of glass actually cracked. I didn't know they got that hot. I ended up getting four small pieces of 1 inch block and sat the lights on the blocks so the bulbs are now about 2 inches above the glass. I noticed tonight another piece of the glass is cracked:;fru. How high above the tank is it recommended that cfl bulbs be. Also my ballast get very hot, I am new to these lights, is this normal or do I possibly have a problem? The are not hot enough to burn me but you can't keeps your hands on them more then a few seconds.