your intake should be smaller than your exhaust to create vacuum. same size vents allow for backflow...

consider a cool tube, imo. temps in the eighties are not necessarily bad, but will tip the m/f ratio toward the masculine. i noticed this winter that my plants from seed grown in temps ranging from 62-72 produced 100% females. and we're not talking two plants either. we're talking 19 big beautiful bonnies.

...how often do you water?