i have 340w and 600w and i have to keep them both no closer than maybe 18 inches. the 600w would cook off 3 week old plants just like an hid would but not with heat. the 340 sits about 3 feet up until they get to be close to 3-4 weeks then i start bringing it down. 1000 watt must be like hitting them with a laser. keep it high off them until you get them to flowering then you can a little closer. with that light youd need co2 to get much closer than 18-24 inches. you could also try a diffuser(like a couple layers of window screen) between the light and the plants.