http://www.amazon.com/Aviditi-PTU-68-Reflective-Hydroponic-36-Inch/dp/B004U6WCMY/ref=pd_sim_sbs_lg_2 I was planning to use. 250 watt hps but I am worried about heat and size issues . I do not know how I am going to ventilate it . I was thinking of a 4 inch desk fan from walmart and just taping it to the exhaust flap in the tent . If you click on the link you can see detailed pics of the tent . Please help me out I need some easy and simple ideas for ventilation .