full life cycle considered, HPS is the best all around spectrum for a cannabis plant. if you look at the spectrum of an HPS bulb you'll notice it actually has a lot more blue in it than a metal halide has orange or red. an HPS is very orange, yes, but many people often overlook the completeness of an HPS's spectrum for that reason.
anyway that wasn't your question was it? if you think your bulb is indeed dying out then i would suggest just getting another bulb. the ballast should be fine. you'll get a lot more bud if you keep the HPS in there, but there are plenty of examples of good bud production using a MH lamp. in my opinion, though, changing the spectrum so drastically after the plant being in one spectrum its whole life is just asking for hermaphrodites. your plants expect that cool blue spectrum in the spring and summer. generally stressing out the plant during flowering in any manner, including this one, is best avoided.
peace,
monkey
For example I talked to my buddy who is purely ebb/flow hydro and said i was gonna throw some molasses in my fert sched and he laughed at me and called me an idiot, yet i read a lot about it saying it is a great idea. So he gave me this stuff called Purple maxx to use and some King neptune fish fertilizer 1-3-2 and said it was all i needed. I took it, I'm not one to turn down free nutes (hehe) but I'm not changing my mind on the molasses. But its this whole Light debate that irks me more then anything.
