1 Round fluorescents, do to the inside of the bulb being the least amount of light emited from the bulb.
2 Most use a electronic ballast , which is the cheapest way to light a bulb , and fastest to deminish the bulbs life.
3 The object ot grow is to get the most amount of light per watt.
That is why industry uses a mag ballast and 2,4,8 ft florsents.
The same goes for CPF, most of the bulbs output is reflective not direct.
This way is quite common for kids to grow pot, but one of the least efficent way to grow.
Watts always wins, Watts are always the bottom line.
Have fun and wait for the great smell of growing pot.