Hi, I am a new grower with a question. I am considering using a HTG supply Cooltube reflector OR one of the open air double parabolic horizontal reflectors. If I use the cooltube, I can get my lights a lot closer to the plants without worrying about the heat, but I am skeptical that they are efficient because of the internal light reflection from the housing itself. By the way, I am planning on using four 600 watt high pressure sodium lamps, organic grow. Any experienced growers that can help me? I'd appreciate it.