2.7 grams per watt Leds, truth or hype?

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FastFreddi

FastFreddi

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Run 1154 true watts mixed led ...Timbers are main lights, and Mars sp250 and 150's added.
I run early flower low 80's, then drop to mid high seventies late flower.
In a room that is 6x 12ish feet...main lit area is 3.5ft x 6....
Plants love it.
Day 11 since 12/12...canopy about 84 f right now.
20210401_075837.jpg
FF
 
.Smoke

.Smoke

Well-Known Member
FastFreddi said:
I just realized that really has f all to do with your thread@.Smoke...sorry Bro.
FF
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No worries man. It's actually a big help. I must admit I've never really paid too close attention to what people are actually pulling with their LED's. Most discussions I've seen center more about what people's lights are made of, instead what they're actually getting from them.

Yours look great.
I've already begun to change my environmental over from 74F/50RH under HPS and had planned to run around 81-83F/50RH.
My lights off temp will vary depending on how much the dehumidifier runs, but will be between the 70-79F range.

I'm thinking that should be okay? Anything I'm missing?
 
J

jonnynobody

Well-Known Member
.Smoke said:
So I'm switching to Led from HID. The "goal post" for me has always been, "1 gram per watt and you're doing good" with hps.

I'm wondering if, and how close, you all are at actually harvesting 2.5+ grams per watt from your Led setups?
Is this feasible? Or is reality more like 1.5, 1.7, 2.0 etc etc..?

I'm just looking for a good starting point to shoot for without trying to get my expectations too high.
Any input is appreciated.
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2.5g/watt is fantasy land. Believe not sir :) I've done 2 flower cycles with a 660w qb and a 450w qb. There is no increase in yield versus HID. You're saving electricity and not haggling with air cooled hoods and ventilation. Nothing more. Yields are the same as HID. It's not like the plant suddenly says, "Oh shit, this cat got an LED. Okay girls let's kick out 2.5gpw" :) I ran the same strains both cycles. These same strains I rain in HID only as well. Same yields. Just saving electric costs. I will also say penetration in the canopy is better with HID. In a nutshell I lost canopy penetration in the areas I added qb's whereas canopy locations with HID lighting have deeper light penetration. I personally don't plan to purchase any more HID's, but these are the differences I've observed in my garden.

Bottom line: switching to LED isn't going to suddenly increase your output. You will save electricity. Nothing more.
And regarding canopy penetration: If you effectively manage your canopy and spread your branches apart properly the penetration issue is resolved.
 
J

jonnynobody

Well-Known Member
shroomhaze said:
Most aim for 1 gram per watt kinda thing, in my opinion, it's mostly about the strain and the pheno. If it's all about shooting for the biggest yields; you choose strains that yield and produce huge buds. You can get a lot this way, gram per watt thing is really misleading anyways
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Spot on sir. Strain, pheno, and the grower's skills determine yield assuming you have adequate light coverage regardless of the type of hardware used. I've got a ghost train piece of shit that yields horribly no matter what I do, then I've got jager and blue dream taking over my whole dam flower room. Did I do anything special? No. Did my light do something special? No. Did god do something special when those amazing genetics came alive in that seed? You bet your ass :)
 
J

jonnynobody

Well-Known Member
Luvtheflower said:
I average about a 1.7 g under 2 500w led.It isn't really about weight to me I shoot for higher quality buds over quantity.I'm about to start my first auto flower (mephisto orange haze)as soon as these lady's our finished.
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Good god man! Look at her drip with frost. And you look like you're halfway to to finish line. She's gonna be covered in so much sugar by harvest day you aren't gonna see the dam flower anymore :) I'd hang on to those genetics as long as I could
 
evergreengardener

evergreengardener

Well-Known Member
They dont specifiy what diode they run, they just say Samsung led light and they also claim you can pull 2.5g a watt from there burple lights.
they will work but how good is the question,
1617304007120.png
 
.Smoke

.Smoke

Well-Known Member
jonnynobody said:
2.5g/watt is fantasy land. Believe not sir :) I've done 2 flower cycles with a 660w qb and a 450w qb. There is no increase in yield versus HID. You're saving electricity and not haggling with air cooled hoods and ventilation. Nothing more. Yields are the same as HID. It's not like the plant suddenly says, "Oh shit, this cat got an LED. Okay girls let's kick out 2.5gpw" :) I ran the same strains both cycles. These same strains I rain in HID only as well. Same yields. Just saving electric costs. I will also say penetration in the canopy is better with HID. In a nutshell I lost canopy penetration in the areas I added qb's whereas canopy locations with HID lighting have deeper light penetration. I personally don't plan to purchase any more HID's, but these are the differences I've observed in my garden.

Bottom line: switching to LED isn't going to suddenly increase your output. You will save electricity. Nothing more.
And regarding canopy penetration: If you effectively manage your canopy and spread your branches apart properly the penetration issue is resolved.
Click to expand...
Thanks for the straightforward answer. I had a feeling that was the case. But, if I can still manage 4lbs for a fraction of the electric usage, I'll still be extremely happy.
 
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J

jonnynobody

Well-Known Member
.Smoke said:
if I can still manage 4lbs for a fraction of the electric usage, I'll still be extremely happy.
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if you're yielding 4#/cycle right now and you run the same strains and number of plants you will yield the same amount. only 4# is going to feel a lot better in your inventory, because you saved 35-40% on your electric bill for the 3 months it took to grow it. kudos to you for seeing the light. now you got me itching to dump my energy hogs. i'm ready to be done with the insane electric bills. and now you got me light shopping :)
 
cobshopgrow

cobshopgrow

Well-Known Member
.Smoke said:
According to an Amazon review, their service rep stated they're LM281b and osram diodes. 1.9 efficacy.
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if you have your area lit well allready i also dont think youre going to pull more.
as you say, you can save on elctricity which increase your G per W number.
watt is also such a rough measurement as the output of a led could be so different.
1.9 ppfd a watt isnt that high f.e., more recent leds do quite a bit better, especially driven soft.
with modern leds driven soft i think 2.5g a watt isnt a too high goal if you have trained your plants halfway good, genteitcs is capable to do it and the grow goes well.
open space or tent is a factor too, as in a tent you use your wattage quite a few percent more efficient.
 
.Smoke

.Smoke

Well-Known Member
jonnynobody said:
if you're yielding 4#/cycle right now and you run the same strains and number of plants you will yield the same amount. only 4# is going to feel a lot better in your inventory, because you saved 35-40% on your electric bill for the 3 months it took to grow it. kudos to you for seeing the light. now you got me itching to dump my energy hogs. i'm ready to be done with the insane electric bills. and now you got me light shopping :)
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I can tell you it's been really nice to see my daily electric usage drop from 100kwH to around 63 already.

Not having the jet engine sound of 2- 8" 720cfm fans running 24/7 is a great bonus too.
 
.Smoke

.Smoke

Well-Known Member
cobshopgrow said:
if you have your area lit well allready i also dont think youre going to pull more.
as you say, you can save on elctricity which increase your G per W number.
watt is also such a rough measurement as the output of a led could be so different.
1.9 ppfd a watt isnt that high f.e., more recent leds do quite a bit better, especially driven soft.
with modern leds driven soft i think 2.5g a watt isnt a too high goal if you have trained your plants halfway good, genteitcs is capable to do it and the grow goes well.
open space or tent is a factor too, as in a tent you use your wattage quite a few percent more efficient.
Click to expand...
I do understand that the boards definitely aren't the best, but for those of you that are running "the best" my question is are you really getting 2.5gpw in your hands @ harvest, or is that just the "theoretical number" you calculated?

I've seen a lot of posts over the years with people who run "the best", and from the looks of the plants they're nowhere near 2.5gpw. More like .5-.75 if they're lucky...
 
FastFreddi

FastFreddi

Well-Known Member
.Smoke said:
I do understand that the boards definitely aren't the best, but for those of you that are running "the best" my question is are you really getting 2.5gpw in your hands @ harvest, or is that just the "theoretical number" you calculated?

I've seen a lot of posts over the years with people who run "the best", and from the looks of the plants they're nowhere near 2.5gpw. More like .5-.75 if they're lucky...
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I have not noticed bigger yields necessarily, but definitely better quality ...I grow decent nugs anyway lol.
FF
 
ҖҗlegilizeitҗҖ

ҖҗlegilizeitҗҖ

Well-Known Member
.Smoke said:
I do understand that the boards definitely aren't the best, but for those of you that are running "the best" my question is are you really getting 2.5gpw in your hands @ harvest, or is that just the "theoretical number" you calculated?

I've seen a lot of posts over the years with people who run "the best", and from the looks of the plants they're nowhere near 2.5gpw. More like .5-.75 if they're lucky...
Click to expand...
I'm liking how my harvest looks if everything continues well.
I will be happy with 1.5 gpw, but my goal is 1.79 gpw... this will put me at 3lbs in my 4x4.
The size of the tent might be the limiting factor at this point though
 
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