light distance?

I have an 18 inch tall plant. SHe is starting to buf. She has lots or white hairs protrudin at all the nodes. I am using a 400Watt HPS. It is in a grow space (closet) of 2x2x4) How far should the top of the plant be from the light? it is about 18 inches away now. My friend sais it should be a lot closer but ii think it will be too hot. I it is 2 1/2 feet tall will she get oo stretched? My friend says I don;t want it too get to tall. But wont it get taller anyway becauyse she is budding? I have a fan circualting air. Is there anything esle I should do for distance? And should i let her grow as tall as she can ithin the space or should i try to kee her at the height she is if can?

Thanks

a foot away is usually a safe distance,
a general rule of thumb is if it isn't too hot on your hand it wont be too hot for the plants, lower it a a bit and try it out.
I sometimes keep my 400 watter as close as 8 inches away from my plants and they dont seem to mind one bit
and as for the height question, it depends on how far along it is, if its still in the first 2 or 3 weeks alittle stretching isnt a bad thing, any later than that and it may be.

Thankss. Seems good. It is not too hot at about a foot away altough it is warm but that is ok right? its hot but not too as hot as if I ned to shy away.
Als does height of plant have anythign to do with bud size? I want to get as big buds as possible, but leep the plant at a reasobale size?

Thanks

with a light that size you can have about 4, 2-3 foot plants, get about 2 ounces of each. as long as its not uncomfortably hot on your hand it should be fine, (this is not allways true, but usually)