THIS APPLIES ONLY IF NO GROWTH HAS SHOWN WITHIN THE PAST WEEK

I have read your problem once again and i think i know the solution to it.....if it's not the case that BobBong suggests, about the soil being toxic.....it should be the following.....you mention that during the day you put the plant straight into the daylight and during the night under a light bulb.....i think that this is the problem....you change constantly environment.....i do not know if you understand what i mean, it's just that the plant (i think) has to be accustomed to an environment so as to develop....maybe again i'm wrong but i feel that you must decide in which light you want to keep it exposed...either the daylight or the bulb