I'm not sure about the Lumatek 600w, I run the Lumatek 400w. I use a HiLux light from Worm's Way. It's about $20 cheaper than the Hortilux. The people I talked to at Worm's Way said that they and their customers believed the HiLux outperformed the Hortilux bulbs in both brightness and length of life. They also said they and their customers feel that the HiLux is the best bulb for the electronic ballast. Hopefully this helps. You can check it out at.. www.wormsway.com

Good Luck!