I never thought I would be interested in a yellow T5 bulb, but after seeing Iconic Reef's sps tank I am haha There sps had some of the best colors I have ever seen and when I looked at the bulbs one was really yellow so I am guessing it is a 6500k? I am only familiar with ati bulbs but I do not think they make a 6500k yellow bulb? For those that run a 6500k or yellow bulb I would love to hear what brand, how many you run and how you like it. Thanks!