How do you keep the heat down in the tent when usi...

fans don't cool the air. you can exhaust the heat to a location that does not flow back into the room your tent resides, but this will not always fix the problem if ambient temps are also high. AC unit... there's really no altenative. Cooling the air or dehumidifying is expensive. Grow in seasons you can avoid these costs if they are a problem. Try growing with lights on at night and off during day... that can often save a few degrees. Anything outside of an AC unit is dependent on context... and just common sense.. if you can't move the hot air elsewhere or your climate is simply hot, there's not much you can do beside a AC unit. evaporative coolers are ineffective. they only impact temp a small amount and will raise your humidity to high levels more times than not -- and at high levesl of RH they don't cool the air one bit. there's no magic solution for this, unfotunately. LED will help a bit... as longn as you get high efficacy lights. There are plenty of shitty LED with a near-hid efficacy and those wouldn't help much... don't just assume LED = less heat, because if they are made cheaply it won't be a huge difference.

lower ur lamp and decrease the power to 25-50%

the HID lights I know of have a fan attachment built into the hood of the light so it all goes out. Maybe you can rig your extractor up to it if yours has that? Other then that not a lot you can do. keep tent door open? run the ac lower? operate it at night when its nromally a bit colder?

Have the HID heat your entire home overnight and don't use the tent.

As a low-cost solution, you can: - Turn your extractor fan up to full power and maintain a higher humidity level, which will cool the air. - Cool the room where your tent is located: if hot air is extracted directly inside, add a tube leading to the outside or another room. - Change the light cycle: light up at night and make it “nighttime” during the hottest times of the day. - Add a small air conditioner: fill the tank every day with very cold water and even ice cubes. But as you say, the best solution is to switch to LED quickly ;)