i have a 4x4x4 grobox that i will be dividing in half and extending the flowering side to 2 feet wide 4 feet deep and 7 feet tall...im ordering a 400 hps and an inline or squirl cage duct fan i need to know how to set up the ventilation i will be getting a super sun 2 reflector that has a sealed hood with air coolable vent ends and tempered glass. ...do i vent to push or pull the air ...should i bring fresh air in or suck the air out of the box ...?