thanks bro. i was thinkin about the heater but since the air is exchanged three plus times a minute i dont know if it would help. i actually posted this question as a thread and got no response. so what i did was take a comforter and fold it in half and staple it to the side walls so it hung between the inside of the plastic door way and the pots so air flow could still be exchanged but insulate the pots at the same time. it actually worked as far as keeping pots warm. i just wanted to make sure that i was correct in thinking that cold pots and roots stunted the front layer of plants... by the way nice pics and set up