2.7 grams per watt Leds, truth or hype?

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ttystikk

ttystikk

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MidnightSun72 said:
Kind of funny that the whole g/w thing became a standard when really we should be comparing gram/ KWhr. You can veg 1 plant for 6 months or 6 plants for 1 month. There are 7-8 week strains and 10-12week strains. Huge differences in KWHr spent. Even if the g/w yield would be identical.
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An excellent point; how do you calculate it?
 
ttystikk

ttystikk

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.Smoke said:
Thanks for the honest answer.
It seems harder and harder to come across those nowadays.

I've grown a few big plants in the past, but have never come close to producing a consistent number on anything.
I think I've finally settled on which media and nutrients I like, and now I'm ready to start focusing on getting "everything" else dialed in. Switching to the led I think will make a huge difference with having 6 points of light instead of 2 and the ability to dim them independently. I'm hoping it may turn out to be a benefit for someone growing perpetually and can't keep the canopy level exactly even.
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I think you should aim for 1-1.5gpw, until you get things dialed in. 35W/ft² is about ideal, there's no point in pushing more than that.
 
MidnightSun72

MidnightSun72

Well-Known Member
ttystikk said:
An excellent point; how do you calculate it?
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Your KWhr would be the watts of your lights in veg multiplied by hours a day the lights run multipled by days vegging plus the watts of your flower room multiplied by 12 multiplied by the number of days flowering all divided by 1000 (to make kilowatts)

As an example: I veg 200 plants under a 375w LED for 1 months (30 days). So that would be 18h/day X 375W/hr x30days /1000W/kw = 202KWHr

then into flower
Let's say I have 5000W in the flower room, with 8 weeks flower (~60 days)

this gives 12h/day x 5000W x 60 days =3600KWHR

let's say I ended up with 20lbs of cannabis at the end. This would be quality to 20x 16 x 28 = 8960g

or 8960g/ (3600kwhr + 202KWHr) = 2.36g/KWHR

if we went by the old grams per watt we would just say we got 8960g/ 5000w =1.79g/w

Ok if we redo the calculation but this time take 12 weeks instead of 8 weeks to flower, same veg period. You end up with

12h/day x 5000W x 90 days = 5400KWhr

so you went 12 weeks and still yielded 8960g

your g/KWhr would be 8960/ (5400+202)= 1.59g/KWhr

The 8 week strain and the 12 week strain the g/w method would make it seem as though the same amount of electricity was spent. But it wasn't.

recap: so we got 2.36g/KWHR @ 8week cycle down to 1.59g/KWHR on the 12 week cycle if the room Yielded the same lbs with the same light. But in both cases the gpw number would be 1.79gpw
 
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.Smoke

.Smoke

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MidnightSun72 said:
Your KWhr would be the watts of your lights in veg multiplied by hours a day the lights run multipled by days vegging plus the watts of your flower room multiplied by 12 multiplied by the number of days flowering all divided by 1000 (to make kilowatts)

As an example: I veg 200 plants under a 375w LED for 1 months (30 days). So that would be 18h/day X 375W/hr x30days /1000W/kw = 202KWHr

then into flower
Let's say I have 5000W in the flower room, with 8 weeks flower (~60 days)

this gives 12h/day x 5000W x 60 days =3600KWHR

let's say I ended up with 20lbs of cannabis at the end. This would be quality to 20x 16 x 28 = 8960g

or 8960g/ (3600kwhr + 202KWHr) = 2.36g/KWHR

if we went by the old grams per watt we would just say we got 8960g/ 5000w =1.79g/w

Ok if we redo the calculation but this time take 12 weeks instead of 8 weeks to flower, same veg period. You end up with

12h/day x 5000W x 90 days = 5400KWhr

so you went 12 weeks and still yielded 8960g

your g/KWhr would be 8960/ (5400+202)= 1.59g/KWhr

The 8 week strain and the 12 week strain the g/w method would make it seem as though the same amount of electricity was spent. But it wasn't.

recap: so we got 2.36g/KWHR @ 8week cycle down to 1.59g/KWHR on the 12 week cycle if the room Yielded the same lbs with the same light. But in both cases the gpw number would be 1.79gpw
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That's one thing I noticed was the biggest, instant cost drop was changing the 18/6 veg tent from 600w mh to 150w led. I only need to veg 4 at a time to keep flower full so the 600 was overkill to start with.
Running for those extra 6 hours of veg time makes a lot of difference on savings too.
 
ttystikk

ttystikk

Well-Known Member
MidnightSun72 said:
Your KWhr would be the watts of your lights in veg multiplied by hours a day the lights run multipled by days vegging plus the watts of your flower room multiplied by 12 multiplied by the number of days flowering all divided by 1000 (to make kilowatts)

As an example: I veg 200 plants under a 375w LED for 1 months (30 days). So that would be 18h/day X 375W/hr x30days /1000W/kw = 202KWHr

then into flower
Let's say I have 5000W in the flower room, with 8 weeks flower (~60 days)

this gives 12h/day x 5000W x 60 days =3600KWHR

let's say I ended up with 20lbs of cannabis at the end. This would be quality to 20x 16 x 28 = 8960g

or 8960g/ (3600kwhr + 202KWHr) = 2.36g/KWHR

if we went by the old grams per watt we would just say we got 8960g/ 5000w =1.79g/w

Ok if we redo the calculation but this time take 12 weeks instead of 8 weeks to flower, same veg period. You end up with

12h/day x 5000W x 90 days = 5400KWhr

so you went 12 weeks and still yielded 8960g

your g/KWhr would be 8960/ (5400+202)= 1.59g/KWhr

The 8 week strain and the 12 week strain the g/w method would make it seem as though the same amount of electricity was spent. But it wasn't.

recap: so we got 2.36g/KWHR @ 8week cycle down to 1.59g/KWHR on the 12 week cycle if the room Yielded the same lbs with the same light. But in both cases the gpw number would be 1.79gpw
Click to expand...
I like this approach because it accounts for all kinds of relevant variables that the standard gpW doesn't address.
 
evergreengardener

evergreengardener

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ttystikk said:
Most strains finish their bloom cycle in 8 weeks. Heavy indicas can be slightly shorter, sativas go longer.
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But this comes down to whether you count from first day of flip or first nug forming, someone said earlier 7-8 week strain counting from flip over never seen a plant finish in under 9 weeks most taking more like 10. But I’ve never run a landrace indica so maybe they could
 
PJ Diaz

PJ Diaz

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.Smoke said:
View attachment 4868300
They aren't "top shelf", but @ $150 after taxes I couldn't pass it up. $900 for 1320w of Samsung diodes.
LM281B/Osram UV, IR
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LM281b diodes are substantially less bright than LM301b diodes. You get more light out of 880watts (4 x 220watt boards) using LM301b diodes, than you do with the 1100watts of LM281b boards you have. So while you may have saved a bit on up front costs, you will be paying 25% more a month in power for the same light you could have had with LM301b's. I'm not sure what your power cost is, but for me at the lowest tier, that difference would cost me around $200 a year in increased energy costs.
 
PJ Diaz

PJ Diaz

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evergreengardener said:
But this comes down to whether you count from first day of flip or first nug forming, someone said earlier 7-8 week strain counting from flip over never seen a plant finish in under 9 weeks most taking more like 10. But I’ve never run a landrace indica so maybe they could
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This is exactly 8-weeks from flip. It can be chopped anywhere between 8 and 10, depending on personal preference..

Screenshot (88).png
 
ttystikk

ttystikk

Well-Known Member
bk78 said:
I disagree, but I like my weed ripe. To each their own.

Only about 10%, maybe even less have ever been to my liking at the 8 week mark

Now if we are talking 8 weeks from actual buds forming then yes I’ll agree.
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Conditions have a lot to do with it. Warmer, more nutes, higher RH and CO2 supplementation all combine to push things.
 
DoubleAtotheRON

DoubleAtotheRON

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From my experience with LED for almost 3 years now. Best we've ever done was 1.4g per true wall draw watts. 12,212g with 8,730 true watts. Worst we've done with the same setup/room was .98g per watt. (HLG 550 V2's)... we only count marketable buds tho... no larfy crap, or trim. IF you count the machine trim (which we do love to smoke), its more like 1.9g per watt.
 
.Smoke

.Smoke

Well-Known Member
PJ Diaz said:
LM281b diodes are substantially less bright than LM301b diodes. You get more light out of 880watts (4 x 220watt boards) using LM301b diodes, than you do with the 1100watts of LM281b boards you have. So while you may have saved a bit on up front costs, you will be paying 25% more a month in power for the same light you could have had with LM301b's. I'm not sure what your power cost is, but for me at the lowest tier, that difference would cost me around $200 a year in increased energy costs.
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The 301's @ 22% better efficacy means it will cost me about $11 more per month in energy costs with the 281's. I know a lot more factors go into it, but looking just at the upfront cost difference between the two boards, it will take me quite a while before I'll be spending more for the electric for the 281's than the price difference of going with the 301's.

This is just the beginning of me dabbling in the LED world and if my history with hid holds true, these will be far from my last light purchase.
If led works for me I'm sure I'll upgrade soon enough.
 
.Smoke

.Smoke

Well-Known Member
Johnny Lawrence said:
I tried to talk him down from the ledge. He claimed he ordered all of the Amazon lights 4 or 5 hours prior. He still had time to cancel, if not return, the order. You can lead a horse to water.

It trips me out that an RIU reg, with access to the knowledge that is available here, would go and buy such shit lights.

Oh well.
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^^^^
This is a great example why I stayed away from the Led scene.
Wtf is it with you guys about light specs?
Is it your version of muscle cars?

Anyone likes the lights?
Great

Don't like them?
Fine also.

It will just taste a little sweeter then when I harvest in 1 plant with my shitty lights what others get from their whole tent with their "top shelf" equipment.

At least that will still be the same as when I ran my "barn lights" too...:rolleyes:
 
MidnightSun72

MidnightSun72

Well-Known Member
.Smoke said:
^^^^
This is a great example why I stayed away from the Led scene.
Wtf is it with you guys about light specs?
Is it your version of muscle cars?

Anyone likes the lights?
Great

Don't like them?
Fine also.

It will just taste a little sweeter then when I harvest in 1 plant with my shitty lights what others get from their whole tent with their "top shelf" equipment.

At least that will still be the same as when I ran my "barn lights" too...:rolleyes:
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Lol it's not that. It's just people normally "invest" in LEDs for their efficacy, so going with a less efficient fixture pushes your ROI out if you didn't save much on the light.

That being said I think almost any LED is easier to grow under, it's definitely easier to work under the fixtures while they are on. Easier to cool because it's not beaming that heat into the plants, easier to make the coverage you like etc. There are a lot more reasons to switch than I originally counted on when I first bought LEDs it was just for their efficacy.

I don't get too attached to any one technology... I have CMH HPS and LEDs and use all of them.

It's funny some consider their choice in light some kind of reflection of who they are as human being lmao. I
 
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