CFL's are what I use. Get the most powerful bulbs you can find. I'd start out with 6500k for the growth period, and switch to 2700k for the flowering period. Put them as close to the plants as possible without burning them. CFL's don't put out much heat, so you can probably get them within an inch. Note: CFL's put out more light when placed vertically as opposed to horizontally. But you really need to spend hours, and days doing research on this stuff. ALL the information you are asking for is right here at Rollitup.org... nutes, soils, lighting, everything. This is a labor of love and a passion for those here.. it is an art-form... not something that can be placed in a single post.