If they are the standard T12 42 watt, I would say . . . maybe. It really depends on the shape of your grow room. They use 42 watts, and the max lumen output i have seen on them were 3400 lumens. That was in cool white. The best spectrum for veg is 6500k, which the T12 version has around 2700 lumens if I remember correctly. Tbat is per bulb by the way. Compared to CFLs, they are about equal. The thing is, the flourescent tubes are long and thin, and disperse light VERY broadly. A LOT of light is lost with them, unless that is, you are putting your plant in a corner and leaning the flourecent againts the wall to basically cover the plant with light. Personally, i would stick to CFL's for vegging, since they are much more adjustable and can fit in smaller areas, and of course for flowering it is dumb to use anything but an HPS.