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Grams Per Day: Determining Cannabis Yield Success by Weight

Marzbadrock

Plant of the Month: Sept 2015 - Nug of the Month: Jan 2016, May 2018
I'm really a calm kind person, I just don't want wrong info out there or for me to be wrong n spreading shitty info! I don't care if I'm wrong, show me so I know! I hate text cuz things come off wrong. Just want all to be on same page. Great discussion tjough, more input info from anyone I'd love to hear it
 

gr865

Well-Known Member
A quote from the article.

"Here’s an example: 1,000 grams yielded ÷ 1 light ÷ 70 days in flower = 14.29. So this single light’s crop had a gram per day (GPD) average of 14.29.
No matter how large or small a crop is, it can be measured as such, allowing an equal playing field of crop analysis irrespective of crop size or time it takes to flower particular genotypes.
Here’s another example from a larger batch: 58,453 grams yielded ÷ 75 lights ÷ 67 days in flower = equals 11.63 grams per day."

That's where I was saying it is useful for the hobby grower.
If you and I were growing in the same size tent, same lights and same strains, you come up with 4 GPL more than I do, I would want to know what I did different from you so I can correct my grow. Does that make sense?
I am always looking for ways to improve my grows.
 

Marzbadrock

Plant of the Month: Sept 2015 - Nug of the Month: Jan 2016, May 2018
Yes 100% makes sense and I agree 100%.
I guess I'm either misunderstood or not understanding something. My whole thing was with the whole 17 grams a day thing.
Just forget the light for a second.
Yield ÷ days = gram per day correct?
 

Marzbadrock

Plant of the Month: Sept 2015 - Nug of the Month: Jan 2016, May 2018
650 grams ÷ 63 days = 10.3 gram per day right?

10.3 gram per day ÷ 630 watts = .0163 gram per watt per day right?

Now you could through sq. Footage in there n figure out in more detail.
 

Marzbadrock

Plant of the Month: Sept 2015 - Nug of the Month: Jan 2016, May 2018
Just for shit n giggles lats say you use 1000w. The only thing changing is size of light.

650÷ 1÷ 63 = 10.3
The size of the light can't determine your gram per day. Your gram per day determine your gram per day
 

gr865

Well-Known Member
Just for shit n giggles lats say you use 1000w. The only thing changing is size of light.

650÷ 1÷ 63 = 10.3
The size of the light can't determine your gram per day. Your gram per day determine your gram per day
Ahh but you did not factor the light into the last formula, if you did that it would be,

650 / 0.63 / 63 = 16.4 GPLD
 

Rider509

Well-Known Member
Maybe rider can just clear something up for me so i know. Maybe I'm just missing something obvious.
20.8 per 1000w used?
33.3 grams a day for 1600w
Hahaha, no way. I started this shit but I'm not finishing it! I'm making popcorn. Shed is right. That guy's formula doesn't work for less than 1000W lights. If I'd spent an extra few minutes thinking about it I'd have probably never shared it here because it seems better suited to large commercial grows.
 

Marzbadrock

Plant of the Month: Sept 2015 - Nug of the Month: Jan 2016, May 2018
It does not work! Thankyou! I see where the confusion coming from but I just can't explain it correctly I guess. Oh well, I know what I pull per day per watt cost per gram.
 

Marzbadrock

Plant of the Month: Sept 2015 - Nug of the Month: Jan 2016, May 2018
If you take harvest÷days = gram per day then divide by wattage you get gram per watt, you can multiply that by hour of light used n figure gram per hour.
 

gr865

Well-Known Member
Hell it really don't matter, I am a hobby grower.
I know I can pull 1 plus gram per watt, and that depends on strain I am growing.
Last grow was only .8 gram/watt but that was LSD and it did not seem to be a big producer, plus had a couple of issues.
 

Marzbadrock

Plant of the Month: Sept 2015 - Nug of the Month: Jan 2016, May 2018
Just example

648 gram harvest in 63 days with 420 watt light
10.285 gram per day ÷ 420 = .0245 gram per watt

If it were two 210 watt lights then it be 5.14 per light
 

InTheShed

Member of the Year: 2018 - Member of the Month: Jan 2018, Nov 2018 - Grow Journal of the Month: Aug 2018 - Plant of the Month: Oct 2018
Is 630 not 63% of 1000?

Don't see why the formula won't work under 1000 Watts
Because, as I said above, when you divide by a fraction you get a bigger number. When your dealing with percentages you multiply. See my example previous.

This formula is not in watts, it's in units of 1000 watt lights.
 

Rider509

Well-Known Member
Is 630 not 63% of 1000?

Don't see why the formula won't work under 1000 Watts
Looking at it again, I'm not sure it doesn't. Remember that this is a way of comparing yields across many different types of grows regardless of size.
1000grams / 2 (1000W lights) / 100 days = 5 grams per light unit per day
1000grams / 1 (1000W light) / 100 days = 10 grams per light unit per day
1000grams / 0.5 (500W light) / 100 days = 20 grams per 1/2 light unit per day

No matter how you slice it the guy getting 1000g using 1/2 light unit is slaying the grower that's getting 1000g using two light units. I think it's the nomenclature that's screwing us up. It's incorrect to call it grams per day without clarifying that it is relative to a specified unit of lighting.
 

Marzbadrock

Plant of the Month: Sept 2015 - Nug of the Month: Jan 2016, May 2018
Looking at it again, I'm not sure it doesn't. Remember that this is a way of comparing yields across many different types of grows regardless of size.
1000grams / 2 (1000W lights) / 100 days = 5 grams per light unit per day
1000grams / 1 (1000W light) / 100 days = 10 grams per light unit per day
1000grams / 0.5 (500W light) / 100 days = 20 grams per 1/2 light unit per day

No matter how you slice it the guy getting 1000g using 1/2 light unit is slaying the grower that's getting 1000g using two light units. I think it's the nomenclature that's screwing us up. It's incorrect to call it grams per day without clarifying that it is relative to a specified unit of lighting.
No arguing with that. I think grams per day per watt is correct. Or grams per light unit . But if we want absolute certainty then gram per day per watt per sq ft. Would be the best way I believe. Would work for every wattage, light, tents, rooms, closet, tubs.....
 
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