Would anyone know what 1 plant will produce on average budding under a 400w metal halide? There is 9 plants in total
No guess. Depends on whether you know what the hell you're doing - variety - lighting - LST or SCroG, the list goes on. I could totally fuck up a 400w MH grow wiuth nine plants and get a 28gm harvest or rock on it and get 2 pounds.
You sound like I was! lol I've done 9 before with a 400w MH in 6"-8" pots and I probably would have gotten the SAME THING with 4 plants in three gallon pots, or better. Probably MUCH better 100w per plant, there's really no getting around that in Flowering. Vegging is whole different story, and you can do a bunch with 400w. They take up less room depending on how you do it. My yield with 9? 1/4 oz per plant, tops.
You need a high pressure sodium to flower. A metal halide is the wrong color spectrum for your plant when flowering.
idk if the make a conversion bulb for MH to HPS but you could take a look for those, it would be better, i think ive seen MH bulb made for the red spectrum but idk....
If I remember correctly a 400w HPS "conversion bulb" in a 400w MH ballast takes the wattage down to 360w. Plus they're expensive as hell and not readily available if you need a replacement in a hurry. That's one of the reasons I didn't go that route and just got a separate 600w HPS.
To each their own! I want a 100w per plant in Flowering, ACTUAL! 360w doesn't cut it for me, not even.