Can I use an HPS for vegging? I am about to come into 2 400 watt HPS lights with ballast and have been using CFL exclusively so far. If I use exclusively HPS will I be better or worse off than if I veg with the CFL and flower with the HPS?
I'll chime in with a resounding NO. HPS is a poor choice for vegetative growth. Even Super HPS with enhanced blue spectrum is not as good as MH or 6400K T5 tubes. Red light makes plant stretch and increases internodal distance during vegetative growth. You end up with tall, leggy plants. You could use an HPS conversion bulb, but otherwise I'd keep them out of my veg room.
with out getting all technical, I'd use HPS through out, the difference you see between MH and HPS in veg stages are miniute, so save yourself some money and stick with HPS
Hasn't been my experience at all. I've used fluos, mercury vapor, metal halide and hps during vegetation and I ended up staying with the hps for the entire grow. Metal Halide was pretty damn good though and would consider switching back to that if I got the proper wattage. Your choices, OP? I definitely add my vote to using the HPS throughout the grow.
Do whatever works for you. I'm glad you have your preference nailed down. I suggest the OP read some published, peer reviewed studies on the subject, read a few of the more popular books on grwoing Ganja. Then experiment with different light sources to see what works best for you, and the particular strains you want to grow.
Dude i use nothing else mainly cause that's all i have, and out of a 5x5x5 flower room with 2 plants i average 3/4 pounds every 8 - 10 weeks, depending on the strain of some of the best smoke in the state, imho. I've been growing for 26 years, most growers are not going to know the difference...yes if you wanna get snobbish and technical then yes MH is better to veg under.