I'm having trouble keeping my box warm enough. It's in an area that can get down to 50 F. I have a 400 wt MH with an air cooled reflector and the box vented with a 6" voertex fan... I put a little heater in the 4x4x4 box - but it can't get the temp up enough (70-75F) -- I'm thinking of unplugging my light cooling fan - to get heat from the light? Thanks for some ideas...