I'm buying the Catalina 4x 54w, T5 HO 48" light fixture. The mounting "legs" have to be purchased seperately. My question is, do I need them? I have a glass canopy so I'm not really worried about melting, but does it need to be raised up to help with cooling circulation? Or, can I just put it on top, like my old fixture, and let the built in fans worry about cooling it?