Lumens don't matter bluecraze08. The spectrum of light that the bulb gets it's lumen rating is the spectrum that plants are least sensitive to.

I'm going to use this: http://www.specialty-lights.com/901154.html with the eye hotilux blue bulb. I am going to grow with this because it will allow the plants to grow almost right to the bulb and this bulb has the best spectrum I could find. I may supplement with an Argosun red or gold during flowering.

Is that the system your using? I don't know what to tell you about the conversion bulbs, I don't know much about them.

Happy growing.