Ok so I have a 5x5 tent with a 1000 watt hps. I have a 6 inch 440 cfm exhaust fan that runs through a cool tube and then outside. Currently I am just opening the 3 or 4 intake flaps around the tent and letting the 6 inch suck fresh air in. Question is should I have a intake fan bringing fresh air in? If so how many cfm. My temps and humidity are pretty much perfect.