THC potency vs day of flowering: any data?

cannabineer

cannabineer

Ursus marijanus
Dr. Who said:
Link to what?

It's simple...The way our industry posts THC concentrations is always by volume.

Punch in any strain request on Google.. Look for THC concentrations......What do you get?
A percentage!

Send a sample to a testing lab. What do you get for THC concentrations and Terp concentrations?
A percentage!
These are broken down by exactly what THC compound it is too. Same for terps.

Done by gas-chrome.

Percent = VOLUME

When doing lab work in college. No matter what we were focusing on. Was by far, measured by volume.
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Yes, but what is your tell that it is w/v and not w/w?

Gas chromatography does not specify weight v. volume.

So, why is my presumption that a percentage being listed as w/w is not valid? (That is how I did it in grad school.) It's something of a convention in pharmacy and med. chemistry.
 
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beepy1

Member
Dr. Who said:
Send a sample to a testing lab. What do you get for THC concentrations and Terp concentrations?
A percentage!

Done by gas-chrome.

Percent = VOLUME

When doing lab work in college. No matter what we were focusing on. Was by far, measured by volume.
Click to expand...
Of course if you are using HPLC or gas chromatography you would use volume measurements during the tests since the instruments require liquids. This is also irrelevant since it can be easily converted to w/w percentage if you know the density of THCA and its comcentration in solution. What you are trying to tell me is when a cannabis dispensary or testing lab says SuperDank Kush is 10% THC they mean 3mL of THC for every 30mL of dry material? If not, please explain what you mean.
 
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beepy1

Member
Thundercat said:
Your a smarmy one aren't you. There are many labs that do testing on Cannabis, and many have test results posted on their websites, go check them out. You will notice drastic inconsistencies even among tests of the same strain. That is because of the variables that we tried to express to you, but you didn't want to hear. Strain differences, phenotype differences, and environment. None of us said we knew how much of anything was in our plants, we said it changes between plants and that we hadn't seen the data your looking
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I have seen differences in measured THC for the same strains, but never the same plant tested at different points in its life cycle. Maybe there is an interesting pattern there that could be enlightening, even if there are differences in growing conditions. For example, maybe if these tests were done we could know that at the halfway point of a strain's flowering life the THC would be APPROXIMATELY 30% of the final potential. I wanted to know a rough estimate if nothing else, whether it would be 1% or 90%. I wasn't expecting anyone to say there is a formula to exactly predict THC percentage at any time.

You are saying there are too many variables, but you are basing this from the final THC results from some testing labs? Have you seen a single strain very by a factor of 10 when tested at different labs? If not, I would like to know why you think it varies so much and why my original question is essentially unanswerable? You have helped me with my grow issues before and you didn't need to know my strain and all my grow conditions exactly, so there must be many universal qualities of the cannabis plant that allows you to provide help.
 
Thundercat

Thundercat

Well-Known Member
I havn't personally had any samples tested yet sadly. However I have seen lots of test results at this point. I have not seen one strain sample from a specific grow taken to multiple labs for comparision testing, that would be great info! Many labs have listings for tests of the same strain which show decent fluctuations between phenotype/growers. Its definitely an interesting topic. I have in no means tried to brush it off.
 
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beepy1

Member
Thundercat said:
I havn't personally had any samples tested yet sadly. However I have seen lots of test results at this point. I have not seen one strain sample from a specific grow taken to multiple labs for comparision testing, that would be great info! Many labs have listings for tests of the same strain which show decent fluctuations between phenotype/growers. Its definitely an interesting topic. I have in no means tried to brush it off.
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I didn't feel like you were brushing me off earlier, but I feel others were.
I'm hoping tests like these are done someday too. It could give some fantastic insight into when in the life cycle cannabis generates different compounds, and could also show differences or similarities between strains or different crops under different growing conditions (and differences in a single strain but different phenotypes).
 
Dr. Who

Dr. Who

Well-Known Member
beepy1 said:
I have seen differences in measured THC for the same strains, but never the same plant tested at different points in its life cycle. Maybe there is an interesting pattern there that could be enlightening, even if there are differences in growing conditions. For example, maybe if these tests were done we could know that at the halfway point of a strain's flowering life the THC would be APPROXIMATELY 30% of the final potential. I wanted to know a rough estimate if nothing else, whether it would be 1% or 90%. I wasn't expecting anyone to say there is a formula to exactly predict THC percentage at any time.

You are saying there are too many variables, but you are basing this from the final THC results from some testing labs? Have you seen a single strain very by a factor of 10 when tested at different labs? If not, I would like to know why you think it varies so much and why my original question is essentially unanswerable? You have helped me with my grow issues before and you didn't need to know my strain and all my grow conditions exactly, so there must be many universal qualities of the cannabis plant that allows you to provide help.
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Theoretically you are correct BUT, every environment gives differing results. Be it final or at any point in the bloom period.
N availability,
N uptake by adjusted for pH at that time.
N uptake effected by concentrations of other nutrient compounds.
Temps
RH
This list is simply huge!
and each of these also have variables.

While you could plot the bell curve of THC production by the day in bloom of the strain in question. The roundhouse punch to any thought of consistency in that train of thought.

Take 2 clones from the same mother, even off the same branch.
Grow them in different places and with different nutrients.
You will get quite different results.

The potential for about any change in environment. Results in many differing changes in growth by the plant. This includes all parts of the plants growth cycle in any phase of growth...

While we know that the THC production is sort of a "bell curve" in bloom. Environmental factors cause this to fluctuate. To make any kind of across the board chart on just exactly when it's at this or that point. Not really possible......Any charting of this type is a generalization. That is acceptable to understand how THC production by amounts produced at that time period. In a general sort of way..

beepy1 said:
Of course if you are using HPLC or gas chromatography you would use volume measurements during the tests since the instruments require liquids. This is also irrelevant since it can be easily converted to w/w percentage if you know the density of THCA and its comcentration in solution. What you are trying to tell me is when a cannabis dispensary or testing lab says SuperDank Kush is 10% THC they mean 3mL of THC for every 30mL of dry material? If not, please explain what you mean.
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After over 4 decades of growing... The years of college and the lab work done there.
I understand all I need to know by volume measurement.

Please feel free to define your needs by your definitions....

I have yet to see any tester use your train of thought.
 
Dr. Who

Dr. Who

Well-Known Member
cannabineer said:
Yes, but what is your tell that it is w/v and not w/w?

Gas chromatography does not specify weight v. volume.

So, why is my presumption that a percentage being listed as w/w is not valid? (That is how I did it in grad school.) It's something of a convention in pharmacy and med. chemistry.
Click to expand...
I didn't do medical work in school. :hug:

However, I suspect that some of my lab work in Agronomy did resemble some Med chem. As far as how things are measured and recorded. :hug:

I really screwed the pooch on the gas chrom. They convert to volumetric measure.....So the basically uneducated masses of cannabis smokers reading the report.....
Can actually understand it in terms they understand....:wall:

I guess I'm stuck on volume because, as we broke down plant materials to look for contents in lab work.. We reported in volume.

Combine these ideals as most experience them in our hobby..... The most prolific reporting method is by volume....

Hmmm, Confirmation bias......:roll:
 
cannabineer

cannabineer

Ursus marijanus
Dr. Who said:
I didn't do medical work in school. :hug:

However, I suspect that some of my lab work in Agronomy did resemble some Med chem. As far as how things are measured and recorded. :hug:

I really screwed the pooch on the gas chrom. They convert to volumetric measure.....So the basically uneducated masses of cannabis smokers reading the report.....
Can actually understand it in terms they understand....:wall:

I guess I'm stuck on volume because, as we broke down plant materials to look for contents in lab work.. We reported in volume.

Combine these ideals as most experience them in our hobby..... The most prolific reporting method is by volume....

Hmmm, Confirmation bias......:roll:
Click to expand...
Oh indeed. I've been bitten hard on the ass by my own confirmation bias. It's a painful event to have one's own intellectual honesty disproven like that. Annie owns me regularly. It's pure win ... I get my shit straightened out, and she gets the pleasure of dragging an alleged Ph.D. through the rosebushes by the petard I so willingly hand her each time she catches me vetting the data. Think shiatsu massage ... not so pleasant when it's happening but so much better afterward.
 
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curious2garden

curious2garden

Well-Known Mod
Staff member
cannabineer said:
Oh indeed. I've been bitten hard on the ass by my own confirmation bias. It's a painful event to have one's own intellectual honesty disproven like that. Annie owns me regularly. It's pure win ... I get my shit straightened out, and she gets the pleasure of dragging an alleged Ph.D. through the rosebushes by the petard I so willingly hand her each time she catches me vetting the data. Think shiatsu massage ... not so pleasant when it's happening but so much better afterward.
Click to expand...
So much easier to cover one's bruised ego with dirt or fire. Although there were some ugly chicken dinners wherein our asses were excoriated and handed back to us as we had to smile, nod and swallow (hard). Even the glass of wine didn't help. At least I debrided all those dead brain cells for you, you're welcome :P
 
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