Weight ISN'T weight; weed grown under low light conditions is not as developed and doesn't have the same terpene profile.You can get an average of 1.6 g/w with HPS if you spread it out enough. So in theory you could get 1600 grams from 1000 watts, almost 4 lbs. Similar potency too. Here are some tables from The Effect of Electrical Lighting Power and Irradiance on Indoor-Grown Cannabis Potency and Yield.
Apparently the White Berry strain got almost 2 g/w. White Widow was another good yielder. I guess it would be hard to spread a 1000w HPS over almost 4 sq m so you'd probably need several lower wattage ones. Probably about 6'x6' for a 1000w, instead of 4'x4' as most people use. Seems possible actually with a single 1000w if you raised it high enough and had a good reflector. So maybe the new standard should be 1000w per 6'x6' area. Buds might be less dense, I don't know. Still, weight is weight. Notice that 600w/sq m yields pretty much the usual yield reported by growers who use that, around a gram per watt maximum.
My buds under 11/13 could break a window.Don't you find reduced potency with the 11/13 the last 2 weeks? I don't think reducing it from 12 will actually help anything. I reduced to 8 hours light on the last week of my last batch and it was less potent and there was no ripening effect that I could notice being different from 12.
I do sometimes use 13 in early flowering, after the first week of 12 to get them into flowering quickly, to give increased plant size and long colas. I wouldn't use it when there are significant buds in full development though, because it makes them get leafy and loose. There's no serious buds until week 6-7 so before that it seems to be helpful.
This is the gateway to a lot of fascinating design choices. I've been on the low PPfD side of things and did well, but better spectrum and higher intensity made am enormous difference in quality, even if gpw suffered somewhat.Yeah maybe. It's a matter of whether you want the most weight per unit of area or per watt of power. As the table shows, you'll get more weight per meter with the higher wattage, but it won't be as efficient for power. It's the diminishing returns effect.
I favor high light levels myself, but I'm trying for max weight in very limited space. The higher intensity penetrates better. With lower levels I have a lot of bottom die off. I like 50-60 w/sq m.This is the gateway to a lot of fascinating design choices. I've been on the low PPfD side of things and did well, but better spectrum and higher intensity made am enormous difference in quality, even if gpw suffered somewhat.
On the other hand, too much light is just too much light.
Max yield in limited space needs higher light intensity. I did it with COB LED, which also addressed heat issues nicely. With COB LED, one can have very strong lighting with less than 40W/sq ft.I favor high light levels myself, but I'm trying for max weight in very limited space. The higher intensity penetrates better. With lower levels I have a lot of bottom die off. I like 50-60 w/sq m.
Yeah the COBs are great, but now I also include regular LED bulbs, like 100w replacement A19 or A21. The A21 are larger so they can dissipate the heat better, just can't use them in short spaces. That's where the A19s come in. I leave the diffusers on. Less bleaching and more even distribution. The plants can grow right up into them, though bleaching does occur when closer than a few inches. BTW another advantage over CFLs is that you don't have to worry about getting finger oil on them when you handle them since it's just plastic.Max yield in limited space needs higher light intensity. I did it with COB LED, which also addressed heat issues nicely. With COB LED, one can have very strong lighting with less than 40W/sq ft.
Do the calculation. It works out to 45 grams per square foot. Which is exactly what I stated is the average yield reported by growers. Now let's see you get 85 g/sq ft, which is what you would need to get for 3 lbs in the same space with 1000w. However, if you used the 1000w in a 6'x6' area and got 45 g/sq ft you would have 3.57 lbs, 1.64 g/w.I just find it interesting that at 37.5 watts a sq. ft. I can get 1.2+ gpw now in a 4'x4'.
Yeah, I explained a couple of pages back that this pheno is very fast flowering. Her sisters were done in 55-60 days but this particular pheno has buds look ready at around 40-41 days and a good percentage of trichomes are turning amber around 45. This is my third time running her and so far she's flowering pretty much identically to previous runs. We'll see how she turns out!45 days?
I understand that their is a limit to production per sq.ft. but if i ran 16 instead of 12 with the same (or at least close) production output I can see 2lbs from a 4x4 Which would equal around 56 grams a sq.ft.Do the calculation. It works out to 45 grams per square foot. Which is exactly what I stated is the average yield reported by growers. Now let's see you get 85 g/sq ft, which is what you would need to get for 3 lbs in the same space with 1000w. However, if you used the 1000w in a 6'x6' area and got 45 g/sq ft you would have 3.57 lbs, 1.64 g/w.
You can actually get a 6'4"x6'4" grow tent at Home Depot, which I'm sure would be close enough. Looks rather cheaply made but it's just an example. Couldn't actually find a perfect 6'x6' one. You'd have to grow pretty short plants though I guess, to avoid burning the tops. Or they could just do as you did and use a 600w in a 4'x4' instead of a 1000w as most growers do. It's the most efficient wattage anyway. Were your buds solid enough? Either way, they would get about 45 g/sq ft. Just that they'd be using a lot more power and creating a lot more heat with the 1000w.