3 lbs a light publication
- Thread starter LandAndHeir
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BobCajun
Well-Known Member
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.
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.
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ttystikk
Well-Known Member
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.
GardenGnome83
Well-Known Member
My buds under 11/13 could break a window.
What strains do you run? Where are they from geographically? How long are the days there at flower time? If you run 11/13, plants express more naturally. They are more potent, as well. Not to mention they finish a week faster on average! This extra week makes up for any lost yield, but the buds are better, so i would never go back. There is a lot of science on this, but you have to be open minded and ditch the faulty shit of the past to gain anything from it. I think 12/12 is popular because of a study on chrysanthemums being induced with 12/12. I think it was in a jorge cervantes book i was given like 10 years ago. We owe it to the industry to get it right, and kill the misinformation. We aren't growing mums.
ttystikk
Well-Known Member
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.
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BobCajun
Well-Known Member
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.
ttystikk
Well-Known Member
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.
BobCajun
Well-Known Member
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.
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DirtyEyeball696
Well-Known Member
I've already pulled 3 lbs a plant
Where you guys been
OG#18
Where you guys been
OG#18
boilingoil
Well-Known Member
I just find it interesting that at 37.5 watts a sq. ft. I can get 1.2+ gpw now in a 4'x4'.
BobCajun
Well-Known Member
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.
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ttystikk
Well-Known Member
I did something very similar, long ago. I built my own light rotator and had it going around a 40" dia circle, concentric with a round grow space about 6'6" across, roughly 33 sq ft.
I ran two bloom stages of six plants each in there a month apart and pulled an average of 4 oz per plant. 4x6=24 zips a pull, monthly = 3lb under a VERY tired 1kW SE HPS lamp.
Nowadays, peeps run two lamps in the same space and get an extra pound. The value of the crop makes the tradeoff easily worthwhile.
I ran two bloom stages of six plants each in there a month apart and pulled an average of 4 oz per plant. 4x6=24 zips a pull, monthly = 3lb under a VERY tired 1kW SE HPS lamp.
Nowadays, peeps run two lamps in the same space and get an extra pound. The value of the crop makes the tradeoff easily worthwhile.
loftygoals
Well-Known Member
Not sure if anyone's interested but here's my defoliated tent at 30 days since flip. Have also included day 20 (defoliation day) as a comparison.
Likely they'll get the chop around day 45. Looking promising so far.
Likely they'll get the chop around day 45. Looking promising so far.
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LandAndHeir
Well-Known Member
45 days?
loftygoals
Well-Known Member
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!
LandAndHeir
Well-Known Member
That's awesome they are fast
boilingoil
Well-Known Member
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.
I truly believe I can achieve 2 lb. in a 4x4 with a 600.