I agree 600W may be a little overkill for a 2x2x4' tent. Also I noticed your light is really low. The closer it is to the floor the hotter it will be under the light so keep that in mind. I have 2 flat panel LEDs in my 2x2 but they are set as high as they'll go. Not even sure what the wattage is supposed to be equivalent to but I think each one only pulls 15W from the wall. As far as ventilation, I have a 4" fan (no filter) with a sock over the end to keep the light out. And I have a small 5" fan for circulation. Stays pretty cool in there honestly. Haven't had to worry about heat so I don't know exact temperature. Also keep in mind everything you run in there will create heat. So if you have 2 fans, one for intake and one for exhaust, the intake one is creating extra heat and probably isn't really necessary to begin with. Also keep in mind your room temperature will affect your tent's inside temperature so if it's 80 degrees in your house, that's what your tent will usually start around and go up from there. Hope that helps.