I'm flowering in a closet 12sqft with a 400hps in 18gallon totes. I have one sitting on top of a second tote that drains into the first for a cycle effect. I run two fans off and on durring the light to help with heat. Getting between 82-90 for day and 72-78 night.
I plan on my next grow to be two totes set up for 4 plants. Seems to be working good so far aslong as I watch my temps..