I've got another question for my knowledgeable folks at ICM. I am trying to figure out how many and what size fans I should pick up to cool (8) 1000 watt HPS. I haven't picked up the lights yet, but plan on picking up (8) Blockbuster 8". I currently have 2 8" vortex fans (rated at 747 cfm) I was going to use, do you think I need more for 8kw? I was also a little torn between getting the Blockbusters with the 6" ducts vs. the Blockbusters with the 8" ducts. The pros with the 6" are more reflective material, cons less air cooling ability. The pros with the 8" are more air cooling ability, but less reflective material. So what do you guys think about these questions? I really appreciate all the info I have been getting lately, your guy's knowledge is priceless!