Metal halide height above tank

[clancaster23]

Now that I have basically all the room I need to have a metal halide over the tank, what's the average height that most have over the tank without increasing the heat too much? It's a single 250 watt bulb with two pc actinics. Where I had it before it was only maybe four inches at the most above the tank and I had seen it get up to 84-85 on a average day and this is during the winter in PA. I don't mind it going to 82 or so so if I can get that in the middle of summer (AC room) without using a fan, I'd love it but if I might have to use one, I will.

 

[BL1]

I had a 2x 250w MH fixture above my 75g with the normal legs that came with the fixture. So, it was like maybe 4-6" above the water level and it never affected the water temp on my tank.