Light Height for veg?

I have 20 fem SnowWhite seed from Nirvana that I will be germinating when I get this minor question answered.

Stuff:
1000watt MH light
20 fem seeds
8 btu inline fan
mylar [:
2x1000watt HPS lights(flowing)

So my question is...how high/low should i put the MH light above the newly germ seeds? I just want to make sure i don't burn my plants because the 1000watt MH emits a significant amount of heat. Also, when do i know when to raise/lower the light(s)?

-Daniel

Sounds like quite the set-up. Heat is easy to check for with your hand - if it feels too hot to you then it is too hot for the ladies. However I have no 1000w experience to help with the light intensity coming off that. My best guess is to start at 3 feet and go from there.

Thanx,
if i put a thermometer under the light will it tell me the temp of the heat being emitted? i think that would be a very affective way to judge the perfect hight of the light. im just not sure if it'll work.
-Dan

not sure if directly under the light will tell you. i have one hanging in my room and try to keep it at 85 degress in the whole room