How much ceiling height do you have? You need to adjust the light height as the plants grow up to 4-5ft tall or more. Plus, there's heat control issues...in the summer time. You need to stay at 70-85 degrees at the top of the plants.

I would recommend only two 1000 watt lights: until you get your growing system/growing knowledge; worked out...IMO.

If you wanted 18 flowering females...you might have to veg 30 or more seedlings...(unless you use clones or fem seeds)...and separate the males.

I grew 13 females with one 400 watt HID light, in a closet once...but, that another story...:stoned: