i use a 42 (actual) watt 6500 cfl i got from one of the online light companies. it works great for vegging young plants. i think it cost about $15 delivered. they burn so cool that you can get the bulb withing a couple inches of the plant. GL
the air clearing ones work in a 11x14x35 setup with 2 and a carbon pad .............but they got any size u need
for veggie u want 5000/6500k lights
for flowering u want 3000/2700k lights
each plant u have u need atleast 5000 lumens (lumens are the number of candles it would take to equal that light ) 5000 min 60000 max (rule i go by)
last thing a trick i learned take your hand and put it at the top of the plant so back of hand is facing light leave it there 30 secs if the hand is to warm your light is to close