I'm 400W MH in veg (24 hr light) ...I veg, top and bend till shes bushy. 4-6 weeks after sprouting.
I had 6-8 plants to begin with in big 5gal buckets... killed a few and a few sexed, but I kept sprouting constantly.
so theres always something to replace any empty space immediately.
I also rotate my buckets position bi-weelky and give em a 180 degree turn every day or so....
Flowering under a 600W HPS... hoping that with super-cropping (topping and bending) and a higher wattage bulb for flower, I can get some dense buds.
Oh yeah, and both lights have hoods, some sort of fan blowing through to exhaust and glass or plexi-glass to control heat.
sometimes in the winter I exhaust the heat directly into a corner of the grow room to get more air flow and temp...
but in the summer I hook it to an outside exhaust for ease in cooling....