to grow 2-3 plants in a closet with only a fan running inside. I can open the the door sometimes and get fresh air from a window but thats it.
Never heard of a 500w grow light. You need to find out what kind of lamp it is as many types won't work for growing. That said any type of 500 is going to require ventilation, in a small space I would use an air cooled reflector.
IM planing on getting a hps light, so really my question is it possible for a plant to grow in a closet?
Yeah its possible to grow in a closet...but it all depends on what kind of lamp u got........ Growing out of my closet........just make sure you got a fan in there.....a C02 generator helps alot more so u can get fresh air in............
Yeah, just a fan is fine. Make sure to open the closet door while you're home to exchange the air. Just don't get the light too close to the tops of the plants.