Environment Control In A Tent

I am running a 600w HPS in a 4x4x6.5h with a 440 CFM inline fan pushing air into the tent with vent holes at the bottom for airflow to blow out (I hear this helps with pests)... however, since this is my first tent, I don't have any idea how the temperature/humidity is going to react when the bulb is fired up. I have a thermometer/hydrometer but just for monitoring... I will need to make the adjustments myself to make sure that the temp stays where it should. Do the inline fans that you buy have controllers for speed so you can adjust that? If not, then I am out of ideas.. I hear that I should use about 78 degrees during veg and 82 during flower, the entire time with a 10 degree temperature drop when she is not getting any light. Dark periods also worry me when it comes to keeping the environment where I want it because now I won't have a heat source, but I plan to let the vent run 24/7, so will it get too cold?

you can use a controller for the inline fan heres one on amazon http://www.amazon.com/Hydrofarm-ACSC-Duct-Speed-Adjuster/dp/B003URBQ1M/ref=sr_1_sc_1?ie=UTF8&qid=1327220851&sr=8-1-spell kinda gives you an idea of it, im still a newbie so the other questions im not sure on, since i havent started my first grow yet

If it your only exhaust fan then i'd have it at the top of tent pulling hot air what rises straight out of tent, then you will have fresh air pulling in from the sides.
I had the same prob in a 1mx1x1.6 the heat of my 600Hps was to hot for the exhaust that came with the complete kit(only 155m3h/carbon filter is 173mh3) was not suffient enough so i looked on Ebay and bought an exhaust fan with temp/speed control 355m3h as i', week 6 into flowering and high temps will stump the growth make the thirsty as because im also growing with hydro it brings other probs like plants not drinking nutrients and only water is a classic sign of high temps, as what will happen then is maybe your ph may spike but mainly your TDS/PPM will spike causing more probs and this is why heat is a worry for most.
Also as i'm a newbie myself i will say be very careful what you listen to, i mean after any advice go check it out google search as i have been told a few different things about heat/temps as i was told they would be fine @92 degree so with this i chose not to sort the prob then over a month later every1 i'd spoken to told me why not to have high temps and when i found out about why my ntrients TDS/PPM meter was spiking it all made sense. Just want to avoid any disapointments thats all bruv Peace bro Happy Growing.
P.s come check out 420 magazine very simliar site m8 safehttp://www.420magazine.com/forums/frequently-asked-questions/156956-my-first-grow-normal.html

i run a 400 watt in a 4x4 tent and i hook the carbon filter up outside, put the exhaust fan right on top of the filter, and run ducting from the filter to the top hole in the tent (heat rises). I also have hooked my ac up to the bottom hole of the tent to control temps but it doesn't help that much since i barely run my ac. otherwise just leave the hole at the bottom open for intake. i would buy that speed controller from amazon thats what i use also. no it wont get too cold. I dont even vent into another room and my temps stay at bay but if you can vent into another room you're golden.