Without a cooltube meaning you aren't gonna use it properly or it's an open hood. If it's a cooltube why wouldn't you use the cool tube as it should be used? Run ducting from one side of the cool tube out of your tent as exhaust. Put an inline fan outside of the tent and connect that ducting, pulling out of the tent. You will pull any heat that is under the light and move air inside your tent. You could properly get away with not even having an intake fan if you just ran a 3ft piece of ducting as an intake, then exhaust would pull any air through your intake ducting. If it causes your tent to flex to much, then add an intake fan. This would create equal pressure, and your tent would be normal. You should probably consider getting some fan speed controllers. They will help bring the sound down a lot, and you can control airflow in your tent.