I have a grow box height of 73cm, I'm planning on growing 1 plant within this space and am thinking about using a 200watt HPS light to do this. With 2 fans within my grow box and an extractor fan (could even invest in some cooling ideas for the HPS) would it be ok to have the light only about 5inches from the canopy as I want to maximize possible height? or would this still be too hot with all the fans etc ?
We'd need to know more than just the height, how wide and how long is the space? Either way, 5" for HPS is pretty close, you can't even put most LEDs that close without burning/bleaching the leaves.