I'm setting up a new 30 gallon tall tank and got some awesome advice on filters from this site, and am now hoping that someone out there would be willing to rescue me from my lighting confusion. When I bought my tank, the lfs owner told me the matching fixture would support plants, but she was out of bulbs. I went off, did my research, printed off Hoppy's Lighting Chart, decided one T5HO bulb would be just the ticket and hit Home Depot, Orchard, and finally the lfs again. At the end of my search, I found out that I have a T8/T12 fixture and no single bulb that fits it can provide even low light for a tall tank. Is my only option to modify it for a second bulb? There's probably room, I'm just a cheapskate and sorta mad at the lfs lady for lying and at myself for expecting her to know anything. Thanks much!