It really doesnt matter, the soil doesnt need light so i would say as long as the temp stays right without light then save on your bill for right now til the seed sporuts then once your seedling surfaces then stick her under the light. if you have cfls stick them close to the sprout if you have MH or HPS then keep light approx. 2 ft away or they will burn. you should see a sprout if the seed was germinated in about 3 days without being germ. about a week