my 250w hps/ 6 cfl 30inx16inx77in grow box have a few questions! +rep

Hey guys here is my grow box take a good look and tell me what you think of it i painted it flat white and have 2 plants in there i have a few questions about it though i am going to be running a 250w hps bulb on a 400w ballast <--- is this possible? from what i heard it is. another thing is the temps outside the box right now are in the 50's and with those 6 cfls on, the temp in the box is right at 75 without the exhaust fan running. now if i were to turn on the 250w hps and the exhaust fan which is the stanley blower mod that pushes alot of air around 1000 cfm ive been told? will there be a drastic increase in temperature? from this point on the temps outside will get lower and lower which leaves me with the question of wether or not to put the hps in a cool tube, i dont think it will be necessary due to the fact that the bulb is right next to the exhaust fan which will be taking out a majority of the heat but at the same time keeping the box in a decent temp range especially when it gets really really cold outside this is just my idea but i want to know what u guys think offer an suggestions on ur mind and help me out +rep

bump........

My only real concern is running a 250 watt bulb on a 400 watt ballast. There are dimmable ballasts (usually digital) that you can dial down the power. I am pretty sure that requires a special ballast and a larger bulb that gets dimmed down. It looks like the rest of your box is in good readiness. You could probably get away with a 400 watt bulb in there if you have the extractor fan on when lights are on. Good Luck with it.

thank you man ill see how the 250w works and then see if i need the 400