I have 2 t12's bout an inch away from each plant but they make no heat i can hold the bulb forever and not even feel anything. I have a fan running all the time. Could under watering also make that happen cuz i put in about 1L and it perked back up, they weren't yellowing or drooping though. I have read that this is a Mg defficiency but i just transplanted about a week ago into FFOF and i dont want to nute burn them cuz that soil already has nutes in it.