I have a viper 150Watt, and I have to say that a love mine with the 14k Phoenix bulb. I havent had any heat issues in my 12 gallon. My light is about 5 inches from the surface of the water. However, if you don't plan on keeping only sps you may want to streer away from the 150 B/C Mine is so bright I cannot keep any sps in the top 1/4 of my tank w/o color loss. I hope this helps.