Ok I built a rf cc is 30”x5’ fb is 24”x20x30” I have a 6” stack 36” tall below rf plate is 7”x14 I have a 2” upper vent and a lower 3x5 vent in fire box it will told 225 for hours but I have. Dirty white smoke can take smoker to 300 still white smoke I leave vents all open and door cracked still white smoke do I need more air vent in fb ??