hope this helps, it's a quote of an answer i gave to someone else on a similar question, anyway, here it is
"if your new to growing and on a budget, buy cfl's, you can buy them one at a time for under ten bucks and, you can buy them locally, and, because you'll be using several smaller blubs rather than one BIG bulb, you can tweak your light spectrum. keep in mind though that you need to look at the ACTUAL wattage and not the equivalent wattage. also look at the color of the light (and i don't mean the bulb, they're all white lol), that will be printed right on the plastic part of the bulb (that's the ballast housing) and it will say something like 6500K, or 3000K, or 2700K etc..., the K stands for Kelvin and it refers to the spectrumor temperature of light the bulb produces.
in veg (which is where your at right now) you want mostly blue light (blue is at the high end or 5000 to 6500K), not ALL blue, but at maybe a 4 - 1 ratio, watt for watt.
when your ready to flower, switch to mostly red (the low end, 3000, 2700 and 1900K)."

good luck
bozo,
peace, love, dope
justanotherbozo Reviewed by justanotherbozo on . Light problem, issues? Okie standard 600 hps chillin with lil babies under it no problems for my friend from out of state (med patient) first week. lil area rigged up with a fan and the light its a good 70-80degrees and slightly humid in their but its find and he says his babies do amazing in his conditions but he called me this morning and said his light stopped working.... When the power was on the fan in the ballast would work but the light it self wouldnt turn on, the bulb he said looked a lil funny wiht black Rating: 5