My room is 4x4 and I have 400hps like 13 inches from the tops of the plants. I am flowering two plants one silver pearl and one purple kush, but the purple has much less buds. Watering: food, water, water, food. Heat: I have a small heater, a fan, the rooms high is 80 and the low is 66. Airflow: I have a 150 cfm exhaust fan. Bugs: I did have some mites but I got ladybug for the problem. Stress: Me or the plant, lol. I cut the fan leaves because of the bugs. Lights: 12/12 13 inches from the top 400hps. Nutes: Bc boost, Bc bloom, Awesome blossoms, Thrive B-1 Red, magical, sugar daddy, PH of the solution= 6.02 and ec=2.6 ms