I have a 2x2x5 foot heigh grow box and a 400 watt HPS, i have a 250mm extraction fan running but it is still too hot in there i also have seven 3 inch vents all around the box what else should i do?? I was thinking of making another big hole like 280mm down the bottom so then it will be cooler i hope and then when i buy ducting for the fan i will have some left over to duct teh vent as well....then if it gets to cold i could fill up the some of teh seven smaller 3 inch vents....does anyone think this will work or have any good ideas!!