I personally am using one right now that is 6 ft long!, running a 600 watt hps, and I am about to buy another 600watt and have the running off the Light mover! You get 25% or more of a yield if you use one,you can get your plants about closer, and it works great because its hitting your plants from several angles several times a day vs the light being stationary. I would use it with a SOG! works a wonder!, I've you are interested i have a video that shows you how to yield 16lbs in 82 days with clones! This will blow your mind away! Im here to help anybody that really wants to learn to grow, I've been growing for 8 years now, I am mainly on Breed Bay, but I have learned so much, and feel the need to spread the love! I remember my first time growing, I hadn't even read any books yet or anything, I just learned from my mistakes and from a old hippie who had the same philosophy SHARE THE KNOWLEDGE! RIP POPS..... Dirty Dozen Crew BB!!