Ok, first off no, a 45 watt cfl will not be sufficient for 3 plants. You will need much more than that especially for flowering. Secondly lumens do not add getting 2 725 lumen bulbs does not make 1450 lumens. Lumens are a measure of light intensity and placing extra bulbs next to eachother does not increase there intensity it only lets you cover more area, so try to go with fewer bulbs of higher lumen rating over more bulbs with less lumens. I also agree that cfl's are usually a better bet than floros because you can be more accurate about where you aim the light and how close you can get the bulbs to your plant(s). Now it is obvious that HID (hps or mh) lights are a better source of light for our purpose, but that is not possible for everyone and you are obviously going to be working with flourescents and they can do the job, though you will get less yield. So basically if you are using cfl's go out and get as many of the highest watt cfl's you can afford and you can fit in your space and try to keep your plants short as the lack of lumens (intensity) cannot penetrate very deep and that is how you end up with terrible fluffy buds. Good luck with your grow.