Well, they have stretched a bit, but nothing too serious. Incandescent bulbs are bad for plants, any kind of plant. They don't produce the correct color temperature or have the lumen output necessary for good growth. You were right for going out and getting a flourescent tube, but it'd be wise to up the ante a bit and get some good CFLs, or better yet, a HID system. You can convert a HPS flood light from Lowes or Home Depot into a good growlight. But if you can only stay with fluorescents try higher kelvin bulbs for vegging [ 4000k - 7000k ] and lower kelvin bulbs for flowering [ 2700k - 3800k ]. Highest -actual- wattage use and lumen output you can find also helps.

Oh, and Miracle-Gro soil isn't bad. In fact, it'd be wise to also invest in a few different fertilizers/nutrients since Miracle-Gro's soil lacks certain trace elements the plant will deplete from the medium before the three months [ if it's the continuous feed ] are up. Contrary to popular belief.