Can I throw my seedlings that are 3.5 days old from seed under a 400 watt mh? They popped there heads out of the soil last night. I have a 4x4 tent that stays around 84F with the light on. I just dont want to give them to much light, and I know I should use floros but I dont have any! also not sure how long I have to use this damn heat mat and dome. advice please!