technically, you could. You would want to create an even canopy and keep the buds within 3 inches of the light, BUT, it's not ideal to flower under fluroros. However, untold thousands of people have grown bud they were happy with under fluoros since the 70s. You won't get a massive yield, and your buds will be airy, but you might be satisfied with what you end up with. Too many people are concerned with perfection and maximum yields when for many people, just growing a small amount of bud for their personal stash is enough for them. If you're okay with that, go for it!