Well, I went out hunting for a Chroma 50 fluorescent tube today and ended up with a Designer 50 by Sylvania instead. The light shop owner looked all over the Sylvania literature but could not find any mention of a Chrome 50? Does anybody know if the bulb has been renamed? If not, how effective will this bulb be in my planted 55 gal tank? The literature states that the Designer 50 is 5000K. Thanks again. Harold