try to see if you can find "daylight" bulbs instead of the warm or cool bulbs. The daylight bulbs are around 6500k on the light temp scale and that is what you need for veg ( very high on the blue side of light spectrum ). I know these bulbs can be bought at walmart, lowes and home dePOT in CFL form but not sure about the 4' tubes. Prob can be bought online at 1000bulbs.com for a cheap price. Also when it comes to the MH and HPS bulbs these also can be purchased at your local Lowes and Home dePOT, atleast in the 400w size. :thumbsup: