All depends on the hood and air cooled or not .
Need a lil more info to be of much help . General noob rule of thumb is put your hand right at canopy height , too hot for you = it's to hot for them .
Peace
Crispi :jointsmile:
xcrispi Reviewed by xcrispi on . HPS question How far away should you keep a 400 watt hps from the plants so that you don't burn them? Thanks! Rating: 5