[
bubbasâ??here's the thing. You need to figure out light production from the lights being used. Technically, you should see the PAR light a plant puts out...but, really, you can get a very good estimate by using color temperature (kelvin) and lumens. PAR amounts for bulbs are really hard to find; bulb temperature and lumens are pretty much universal. I'm a bit confused about your 250w CFL...for one thing, I've never seen that big of a CFL. If it's a 250w equvialent, it should be drawing around 65 watts. Here are some examples of those.

65 Watt Compact Fluorescents

These bulbs put out around 4000 lumens. (CFLS are, at best, around 70 lumens per watt in terms of efficiency, and tend to get get less efficient as they get larger). A 400w HPS puts out around 50000 lumens...about 11 times more. To get as much light, you'd need 11 of those bulbs...and that would be over 700 watts. Which makes sense, as CFLs are (much) more efficient than old style incandescent bulbs, but are about 30-45% less efficient (in light production per watt) than most HPS and MH lights.

p.s. Someone ought to take simpletbrain up on his offer to give away a 250w HPS. I can tell you from experience that a 250w HPS will grow four very nice 26-35" plants in an area of about 5 square feet. You'll need about 15-20 100w equivalent CFLs to match that...and you'll find that heat becomes an issue with that many CFLS too.[/QUOTE]

Hey roughrider,
sorry i havn't checked this thread in awhile. Here are some pics of a 250 cfl these are NOT 60 watt cfl's They are suppose to be 250 watt but real time power consumption is 103 watts. We have built a few fixtures with four of these bulbs together and it only draws a total of 430 watts i'm not sure why we lost some efficiency maybe from the wiring. We will be testing two of these four lamp fixtures for a total of 860 watts and compare it to 1000 watt HPS. With eight bulbs i think the light distribution is going to do very well. Our goal is to grow 2.5 lbs. with these 860 watts. From light measurements our output is neck and neck with the HPS but it is more even at all pionts of our grow area...i think this is going to kick ass.