http://www.prolighting.com/lu100.html... im gona be using it during flowering, im only growing 1 plant, so is 100w's good?
temp is only 2000, it should be 2100. So no it wouldn't be best. Idk whether it would work or how well. This one would be a little better. http://www.buylighting.com/100-Watt-High-Pressure-Sodium-Clear-Mogul-Base-p/s67514.htm A couple CFL's added would prolly work fine. It's only 9500 lumens. It would do 1 plant ok. I'm far from a lighting expert, but I use the 10,000 lumens per plant rule.
I agree, you don't need that much wattage for one plant (but I wouldn't discourage you from doing it if you wanted to). That bulb isn't exactly right for color spectrum (should be closer to 2700k) and the lumens-to-watts efficiency isn't great (95:1 ratio) -- a 250w HPS outputs around 33,000 lumens for example (132:1 ratio). All in all I think you could use that bulb if you also supplement with a few warm-color CFLs.
I think you should grow at least 2 plants just in case one turns out male; or in my case where all three of my plants turned out male.