the light stays on? idk be more specific. um if its HPS or MH it might get hotter. idk what your asking.
it will grow a little faster, but a period of dark is good for the roots. 18/6 or 20/4 would be good for vegging.
i want to grow 2 plants with cfl's both and i want them to be 4 ft or under. leave the ligh 20/4 for its whole life cycle
i would do an 20/4 or 18/6 lighting schedule until there between 1-2 feet tall. and then switch to 12/12 and when they finish they should be between 3-4 feet. (roughly, an estimate)