Go to wal-mart, home depot, ect. and get the GE "Daylight" CF bulb. It actually says 6500K on the package! I think you can get 23 or 27 watts. I think this is just as good or better than anything you get from the petstore. I put two over my 20 gallon along with one 15 watt flourescent strip and it looks great, plants are doing great.