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- #21
Soil ppm
- Thread starter prankster
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- #22
Well I havent read everything but these ratio's were found (last two lines).
Pretty interesting numbers. P does raise a little bit. But most nutes go down. Also Ca. Maybe because of enzyme production slowing down during bloom. To calculate the levels they found in the plant in mg/Kg = ratio* 29333.33. This is for the end of veg and bloom for the White Rhino strain.
N = 1.5*29333.33 = 44000 mg/Kg. Which is what I said before. The 4% rule of thump. A 1 kilo plant contains about 40 grams of nitrogen.
Interesting because subcools recipe for supersoil only contains about 30-40 grams of nitrogen (my estimation). I dont know at what stage of life this soil is utilized by the plant. If repotting is possible it could be giving in three pots.
Gonna think about this
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- #23
This is also an interesting paper. Lower concentrationds of P is negatively correlated to CBD (thus thc) concentration and Mg negatively correlated to THC concentration.
They claim.
Leaf P is positively correlated to the thc levels. P is a bit confusing in this paper
Which means that for high THC content you need to keep the P low and Mg low (soil concentration is < 40 ppm).
It also claims thay a Ca/Mg ratio of 0,74 or higher (less mg) is necessary for a high thc content
Thanks for that. I remember reading some of that paper at some point.
An interesting thing about it, their goal was “to evaluate the practicality of using chemical analysis of C. sativa products to determine their geographic origin.”
The DEA funded them to see if they could trace seized cannabis back the the region it was grown. Thats how they were able to perform cannabis research back in 1975. Fortunately as the paper describes, it was a total dead
end.
High levels of P will inhibit mykos. Most the the N that the plant will need is taken up before stretch. I have heard that the plant takes up almost all the N it needs by the time stretch is done which is why bloom formulas go light on it. The plant will continue to take it up and convert it to ammonium, and thats a waste of energy. And if you think about the biomass the plant is adding at the end, up to 25% cannabinoids, do not contain any of those minerals.
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- #25
Yeah. Im gonna do some reseach on the N uptake in plant. Gonna start with this paper. You have some suggestions for reading material?
(PDF) Is ‘peak N’ key to understanding the timing of flowering in annual plants?
PDF | Flowering time in annual plants has large fitness consequences and has been the focus of theoretical and empirical study. Previous theory has... | Find, read and cite all the research you need on ResearchGate
www.researchgate.net
jamexican686
Well-Known Member
I try n measure my plant ppm by runoff when I water them I measure the ppm of the water fully saturate the soil n water through a bit. measure the runoff n it gives me a ballpark of what my plant is uptaking, or am I an idiot?
Seems sort of ironic to see Advanced Nutrients attach their name to any sort of myth busting. They may not want to go too far down that road....
Other than that maybe, it seems like weed must be pretty tolerant of high P? From nearly everything I read it seems like the P levels are overdone regularly, and if there are serious ill effects such as deficiencies in the plant from moderate P abuse, as there are from most other nutrient abuse, I’m still not sure what they are.
I’ve been running my P levels at about 60 ppm. Considering cutting it in half for a few plants just to see if I can spot any difference at all. Even 30 ppm is a lot higher than most crops from what I understand.
Other than that maybe, it seems like weed must be pretty tolerant of high P? From nearly everything I read it seems like the P levels are overdone regularly, and if there are serious ill effects such as deficiencies in the plant from moderate P abuse, as there are from most other nutrient abuse, I’m still not sure what they are.
I’ve been running my P levels at about 60 ppm. Considering cutting it in half for a few plants just to see if I can spot any difference at all. Even 30 ppm is a lot higher than most crops from what I understand.
The Celt
Well-Known Member
Well, not sure if the OP was referring to growing in organics or salt based fertilizers, and this makes a big difference.
If salt based, then osmotic pressure plays a role but you are not apt to find a “perfect” ppm point that could be used start to finish. Air temperature and rH would also play a role in the uptake along with the water.
As for high P in bottled nutes, it is likely high because it is a nutrient that, when in excess, aid/increases the uptake of other nutes.
If the OP is growing in LOS, or thinking along organic lines, osmotic pressures play a minor (maybe not at all) role in how the plants uptake nutrients. Water is needed for transporting the nutrients through the plant, but is not involved in the absorption of nutrients by the roots. In the case of N, bacteria are absorbed into the root where enzymes break down its protective shell which is high in N, then the bacteria are expelled back into the soil where they feed on organic matter, rebuilding their shells and the cycle repeats.
It took me a long time to stop myself from treating LOS soils by hydro standards, they play by entirely different rules
If salt based, then osmotic pressure plays a role but you are not apt to find a “perfect” ppm point that could be used start to finish. Air temperature and rH would also play a role in the uptake along with the water.
As for high P in bottled nutes, it is likely high because it is a nutrient that, when in excess, aid/increases the uptake of other nutes.
If the OP is growing in LOS, or thinking along organic lines, osmotic pressures play a minor (maybe not at all) role in how the plants uptake nutrients. Water is needed for transporting the nutrients through the plant, but is not involved in the absorption of nutrients by the roots. In the case of N, bacteria are absorbed into the root where enzymes break down its protective shell which is high in N, then the bacteria are expelled back into the soil where they feed on organic matter, rebuilding their shells and the cycle repeats.
It took me a long time to stop myself from treating LOS soils by hydro standards, they play by entirely different rules
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- #29
Well, not sure if the OP was referring to growing in organics or salt based fertilizers, and this makes a big difference.
If salt based, then osmotic pressure plays a role but you are not apt to find a “perfect” ppm point that could be used start to finish. Air temperature and rH would also play a role in the uptake along with the water.
As for high P in bottled nutes, it is likely high because it is a nutrient that, when in excess, aid/increases the uptake of other nutes.
If the OP is growing in LOS, or thinking along organic lines, osmotic pressures play a minor (maybe not at all) role in how the plants uptake nutrients. Water is needed for transporting the nutrients through the plant, but is not involved in the absorption of nutrients by the roots. In the case of N, bacteria are absorbed into the root where enzymes break down its protective shell which is high in N, then the bacteria are expelled back into the soil where they feed on organic matter, rebuilding their shells and the cycle repeats.
It took me a long time to stop myself from treating LOS soils by hydro standards, they play by entirely different rules
OP is based on a tweaked Flora series fertilizer schedule.
A supersoil with 6 g N/L is 30 grams in 5 liter supersoil. So that leaves 10 liters of organic soil in a 15 liter pot. That would be an extra 10 gram of N.
In a 5 liter pot befor repotting it would have got about 15 grams of N.
So in total that would be 55 grams of N. This would correspond to a 1,3 to 1,5 kilo plant according to the 4% rule.
A theoretical recipe could be the following (ingredients mostly from Kis organics and down to earth):
300 gram Crabmeal 4-1-0
300 gram Alfalfa meal 2-1-2
295 gram Kelpmeal 1-0-2
263,16 gram Wormcastings 0,78-0,38-0,16
50 gram potsoil 14-16-18
32,36 gram Potash 0-0-50
2,7 Liter cococoir
tbsp Biochar
tbsp Humic acid
tbs nutrititous yeast
tbs malt
Mycorrhiza
= 5 Liter supersoil (30 gram N - 15 gram P - 37,5 gram P)
Compost
Fill bottom third of 15-20 liter container.
Fill with 10 liter Miracle-Pro potting mix (0,21-0,11-0,16)
= 15 liter
The Celt
Well-Known Member
Morning mate, you are on the right tract. There is enough in that mix for ~1kg of plant matter. Here is the thing though, that 1kg of plant matter would be ~10kg live weight. That is high expectations for 2.7L of medium.
When they refer to a plants NPK makeup, its based on desiccated weights, not live or in our case dried and cured weights.
When they refer to a plants NPK makeup, its based on desiccated weights, not live or in our case dried and cured weights.
The Celt
Well-Known Member
Just to give you some perspective, this plant in 45L of coco would have weighed about 10kg live weight giving ~700g of cured bud
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- #32
Good point. I have to keep in mind the moisture levels of everything.
The medium is 5 liter super soil (containing 2,7 liter coir) + 10 liter organic soil = 15 liter.
I go for potency. They say smaller pots result in more potent buds
The Celt
Well-Known Member
OK, I missed the actual size of the grow pot lol you should be on tract then lol
Potency has never been my top concern and have never had my stuff tested so I have no comment on pot size and potency lol having said that, I have never had any complaints from those that have tried it.
I am an LOS grower, using nutrient dense mixes. I am more interested in the terpene profile than overall potency, and this is where LOS excels.
Potency has never been my top concern and have never had my stuff tested so I have no comment on pot size and potency lol having said that, I have never had any complaints from those that have tried it.
I am an LOS grower, using nutrient dense mixes. I am more interested in the terpene profile than overall potency, and this is where LOS excels.
Enjoil
Well-Known Member
You trying to figure out things that have many different variables. There’s a lot of different factors that are going to impact how well your plant is feeding. There’s amino acids and other additives you can use to get them to do this more efficiently. Stuff like mammoth-p. Just make sure to respect emilya cuz she is awesome and has some of the best help around, you really can’t have much better help than her.... hope I helped a bit...The reason imasking is because im trying to figure out how much a plant is eating in total during its lifetime.
If I integrate the equation for this graph I get a total of 98 grams nutrients / L. (about average of 1150 ppm in 84 days)
b and a = max and min y values. i and j are midpoints of the s curves on the x axis. M and n are the slopes of the curves. And P is the ratio of the two curves y length.
Anyway. I got about 98 grams/ liter soil of nutrients. (thats for a 20 L pot 20*98 = 1,98 kilo of nutrients)
A rule of thump is that a plant consistst of 4% nitrogen. For a 2 kilo plant thats 80 grams of N. Which it can only get from eating.
Yeah. Dont know where im going exactly. Nevermind
Enjoil
Well-Known Member
On the right tractor? Huh? Just playing. Lol. Track maybe? I love all these stoner explanations! Ha ha!
I’ve never heard of that one before. It seems very unlikely. Who is ‘they’ ? They don’t seem to write much.
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- #37
Frontiers | Closing the Yield Gap for Cannabis: A Meta-Analysis of Factors Determining Cannabis Yield
Until recently, the commercial production of Cannabis sativa was restricted to varieties that yielded high-quality fiber while producing low levels of the ps...
www.frontiersin.org
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- #38
Just to give you some perspective, this plant in 45L of coco would have weighed about 10kg live weight giving ~700g of cured bud
Beautiful picture BTW
Sorry I‘m not laughing at you at all with my laughy face up there Prankster. By the time I got 1/4 of the way through that document I was laughing too hard to continue Just taking a break but I’ll go back to it now and try to find the relevant part. But I have to say it just reads like hardcore academic masturbation to me so far 
Edit. Wow. I guess this is what legalization gets us in Canada. I’m embarrassed.
I ended up just skimming through all that bullshit, but I will cut and paste in the final conclusions of that absolutely monumental amount of data.
This is going to be pretty earth shattering so hang onto your seats everyone.
“Conclusions
In order to increase cannabis yield per square meter and per W light, the results of this meta-analysis point to the use of
(1) low plant density (≤12 plants per square meter),
(2) a flowering period duration of 9 weeks,
(3) the use of HPS lamps,
(4) an adequate fertilizer regime, and
(5) manipulating light intensity to preserve high energy efficiency vs. favor THC and CBD accumulation.
Furthermore, our results demonstrate that cannabis varieties respond differently to production conditions.”
Just taking a break but I’ll go back to it now and try to find the relevant part. But I have to say it just reads like hardcore academic masturbation to me so far Edit. Wow. I guess this is what legalization gets us in Canada. I’m embarrassed.
I ended up just skimming through all that bullshit, but I will cut and paste in the final conclusions of that absolutely monumental amount of data.
This is going to be pretty earth shattering so hang onto your seats everyone.
“Conclusions
In order to increase cannabis yield per square meter and per W light, the results of this meta-analysis point to the use of
(1) low plant density (≤12 plants per square meter),
(2) a flowering period duration of 9 weeks,
(3) the use of HPS lamps,
(4) an adequate fertilizer regime, and
(5) manipulating light intensity to preserve high energy efficiency vs. favor THC and CBD accumulation.
Furthermore, our results demonstrate that cannabis varieties respond differently to production conditions.”
I am pretty sure that whoever wrote that has not grown much cannabis before, and it will be more productive to seek out people who actually have. Redcup and @The Celt here clearly know their shit.
Generally speaking I think the idea that smaller pots makes for greater potency is just not true, doesn't make any particular sense, and is not even ‘a thing’. I’ve never even heard of anyone saying that before now.
I didn’t find them saying it in the article either, but clearly I am too cynical to give it my full attention.
I hope I’m not offending you mate I trust you did not write the article yourself and I’m not mocking you in any way at all, I’m just laughing at the article but maybe I smoked a little too much tonight....
Generally speaking I think the idea that smaller pots makes for greater potency is just not true, doesn't make any particular sense, and is not even ‘a thing’. I’ve never even heard of anyone saying that before now.
I didn’t find them saying it in the article either, but clearly I am too cynical to give it my full attention.
I hope I’m not offending you mate I trust you did not write the article yourself and I’m not mocking you in any way at all, I’m just laughing at the article but maybe I smoked a little too much tonight....
