for my first grow i used a 400watt light with two plants in a closet grow, with dry weight being around 200 grams. for my current grow i added another 150 watt light along with the 400 watter, again with 2 plants. at week 3 of flowering im already seeing substantial increase in bud size just from the 150 watt addition. imho, if your growing for yourself with a little to spare, a 400 watt hid is perfect for the budding grower. (pun intended)