Actually those lights you bought look like a CFL, or a flourex...not sure the difference. They will not work very well for a 4x4 area. probably a 2x2 area with baby plants. It probably wont be enough for more than one adult plant.

A cheap route for bigger area would be to go to a hardware store and find the cheapest tube flourescent fixture that is 4ft and holds a couple lights. I've seen the "shop fixture" at ACE which holds 2 4-ft T12 bulbs for $10. Spend another $10 on a couple of cool white lights and you'll have around 5,000-6000 lumens for $20. Get two of these setups side by side and you got your 4x4 area with 10-12000 lumens.

Fade :thumbsup:
Fade Reviewed by Fade on . 500 watt output flourescent light!? http://lightsofamerica.com/wl.htm -I got the the 6165 model (the biggest/ with the yellow colored reflector). the bulb is 3"x3"x 9"L and with the reflector has 4,550 lumens. here are the rest of the specs-Watts Used 65 Incandescent Wattage Equivalent 500 Size (H x D) 17" x 14.5" Lumens 4,550 Efficiency87% Life 10,000 CRI 84 Color Temp 6,500 Rating: 5