Elemental PPM feed schedule per growth phase

2com said:

Cannabis Cultivation and Science Podcast:
Link to Tad Hussey's YT channel: https://www.youtube.com/channel/UCvzklytMGuvSOa4hx0QxhUA/videos

He has great guests on, and great conversation about cannabis related research. (He's had Jeff Lowenfels [author of the "Teaming With" books on several times and there's some interesting discussion in those as well).

Ep. 30, Travis Higginbotham, @46:30 (51:01 mentions 'P' specifically. 12-24ppm.)
Ep. 43, Alison Justice (mentions 'P' specifically. 5-15ppm, references old cannabis study.)
Ep. 59, Paul Cockson (discusses various toxicities, deficiencies, and some published papers they've done. mentions they're currently running, what sounds like, experiments to investigate ranges of specific elements for cannabis.)

All worth listening in full (you can speed up the video/audio by 1.25 or whatever).

Paul Cockson refers to something called the Hoagland Solution, I'd definitely listen to this podcast, and look more into that solution/profile. It might be an interesting starting point for experimenting with nutrient profiles. Note the 'P' in this fertilizer mix, especially compare to everything else (it's 31ppm).:

The Hoaglands Solution for Hydroponic Cultivation – Science in Hydroponics

scienceinhydroponics.com

Britanica and wiki, etc have more information as well.

(edit: added hoagland profile):
N 210 ppm
K 235 ppm
Ca 200 ppm
P 31 ppm
S 64 ppm
Mg 48 ppm
B 0.5 ppm
Fe 1 to 5 ppm
Mn 0.5 ppm
Zn 0.05 ppm
Cu 0.02 ppm
Mo 0.01 ppm

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good call on the Hoagland. just as a FYI it was developed for tomatoes in hydro for one specific week of bloom.

if you look at Steiner formula (i think a better ratio for cannabis IMO) P is 50.
Steiner's formula is here:

• N 170 ppm
• P 50 ppm
• K 320 ppm
• Ca 183 ppm
• Mg 50 ppm
• S 148 ppm
• B 1 to 2 ppm
• Fe 3 to 4 ppm
• Mn 1 to 2 ppm
• Zn 0.2 ppm
• Cu 0.1 to 0.5 ppm
• Mo 0.1 ppm

i would bump Mg up a bit in Steiner if i was gonna use it.

Are they measuring the P and K in those formulas elemental or P2O5 (43%P) and K2O. Both those formulas seem super heavy on Ca. I see the need for fruiting tomatoes to avoid blossom end rot but not sure it’s needed in Cannabis.

Merlin1147 said:

Are they measuring the P and K in those formulas elemental or P2O5 (43%P) and K2O. Both those formulas seem super heavy on Ca. I see the need for fruiting tomatoes to avoid blossom end rot but not sure it’s needed in Cannabis.

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P and K.
Edit: Which formlas? I think the ratio of certain elements to others is the more important thing, not just the level of one particular element. In the hoagland it's 4:1, and the steiner it's just over 3:1 Ca:Mg.

rkymtnman said:

good call on the Hoagland. just as a FYI it was developed for tomatoes in hydro for one specific week of bloom.

if you look at Steiner formula (i think a better ratio for cannabis IMO) P is 50.
Steiner's formula is here:

• N 170 ppm
• P 50 ppm
• K 320 ppm
• Ca 183 ppm
• Mg 50 ppm
• S 148 ppm
• B 1 to 2 ppm
• Fe 3 to 4 ppm
• Mn 1 to 2 ppm
• Zn 0.2 ppm
• Cu 0.1 to 0.5 ppm
• Mo 0.1 ppm

Click to expand...

Cool, thanks for sharing that one.
The higher K and lower P idea, in general, is definitely something that interests me. Tad, and Paul both talked about it in that episode.

There's a "modified hoagland" as well but I think it's barely even any different.

Anyone who's seen greengene's "boost" formula, he explained he was trying to increase P specifically because of purple petioles (leaf stems). It did not resolve the problem. I don't remember when he starts to experience it though (veg? flower? when?).
The purple petiole thing is also a big interest of mine and one thing that got me looking into phosphorus.

That Paul Cockson dude mentioned that a lot of researchers use that hoagland formula, for various crop types. I wonder if that includes other "deficiency" test studies. I didn't know it was designed for one specific week of bloom though. Peak requirement week I guess? It is suggested that you dilute it for younger plants and lighter feeding crops from what I remember (skimming) the other night.
GG uses full strength jacks 3-2-1 from clone to harvest, don't know about seedling.

Vitaly (sorry if misspelled) from ChilLed made a video a while ago with his hydroponic setup and how to mix his nutrient solution (he uses masterblend). I just noticed he has a nutrient profile in the description.
Video link: His profile:
"Working strength nutrient breakdown (approximate):

N - 203 ppm
P - 50 ppm
K - 200 ppm
Mg - 45 ppm
Ca - 220 ppm
S - 50 ppm
Fe - 2.5 ppm
Zn - 0.63 ppm
B - 1.27 ppm
Cu - 0.63 ppm
Mo - 0.063 ppm
Mn - 1.27 ppm
Cl - 12.7 ppm"

edit: Anyone know if @spek9 is still with us? I hope he doesn't mind all this in his thread.

Thats about a 2-1-2.5 NPK ratio. Kinda high on the ca at 220....higher than K at 200.

If ran at lower EC. (Same NPK ratio)
N 100
P 25
K 100

(Ca around 80, Mg 40)

TintEastwood said:

Thats about a 2-1-2.5 NPK ratio. Kinda high on the ca at 220....higher than K at 200.

If ran at lower EC. (Same NPK ratio)
N 100
P 25
K 100

(Ca around 80, Mg 40)

Click to expand...

The 203-50-200 NPK? Wouldn't that be 2-0.5-2 NPK? (You divided each by 100?). If 'P' was = 1 in your first ratio, wouldn't it be 4-1-4 (divide each by 50 to have P=1)?

2com said:

The 203-50-200 NPK? Wouldn't that be 2-0.5-2 NPK? (You divided each by 100?). If 'P' was = 1 in your first ratio, wouldn't it be 4-1-4 (divide each by 50 to have P=1)?

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I was wagging it.

Actual. Based on this calculator dealio...
1.76-1-2.09



It's confusing, NPK Percent ratios vs PPM elemental ratios.



Also used calc to confirm the same ratio, at lower ec.

2com said:

Anyone who's seen greengene's "boost" formula, he explained he was trying to increase P specifically because of purple petioles (leaf stems). It did not resolve the problem. I don't remember when he starts to experience it though (veg? flower? when?).
The purple petiole thing is also a big interest of mine and one thing that got me looking into phosphorus.

Click to expand...

The purple stems are described as a secondairy metabolite buildup by the lack of growth from relative P-deficiency. But actually I see that always occuring in sharp soil, and once a plant brightens up it's becoming better. So I guess other forms of plant food may prevent the plant from either reaching or metabolising it.

Kassiopeija said:

The purple stems are described as a secondairy metabolite buildup by the lack of growth from relative P-deficiency. But actually I see that always occuring in sharp soil, and once a plant brightens up it's becoming better. So I guess other forms of plant food may prevent the plant from either reaching or metabolising it.

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Do you mean it could be anthocyanin, for example, by "secondary metabolite" buildup?
I've heard it speculated being: Light levels (too high, but specifically led). Cold temps (easily ruled out, it's not this). Phosphorus def. Nitrogen def. Overall EC too low. And what would a cannabis nutrient issue be without the suggestion of "CalMag", I've heard that too. And I've heard "strain dependent / genetic", but get the sense that's more of a copout when it can't be figured out (and from experience I've seen it go away, and fairly quickly, which made me think it was a mobile element mostly at play - hence the phosphorus "guess").

TintEastwood said:

Thats about a 2-1-2.5 NPK ratio. Kinda high on the ca at 220....higher than K at 200.

If ran at lower EC. (Same NPK ratio)
N 100
P 25
K 100

(Ca around 80, Mg 40)

Click to expand...

so what's your take on S, Fe & Mn?

2com said:

Fe - 2.5 ppm
Zn - 0.63 ppm
B - 1.27 ppm
Cu - 0.63 ppm
Mo - 0.063 ppm
Mn - 1.27 ppm
Cl - 12.7 ppm"

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I've read somewhere cannabis is a bor-sensitive plant, but this may be hear-say... I'm looking heavily at the micronute ratio from various plantfood and have found some conflicting info's on bor - it's either at the same level than manganese or around 25-50% of Mn.
The same can be said from Mn, which is sometimes even en parre with Fe, but most often ~~50% lower...

I'm finding very conflicting informations on the amount of Chlorine to use in Cannabis... found tissue sample concentrations can get extremely heavy - but that may be due to its abundancy in nature.
Both Na & Cl can both wreak havoc on the ion availability of other essentials.

2com said:

Do you mean it could be anthocyanin, for example, by "secondary metabolite" buildup?

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Yes, indeed. But there are different derivates from these "anthocyanins" thus, the color abberrations.

2com said:

I've heard it speculated being: Light levels (too high, but specifically led).

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so if PAR ramps up due to spectrum & efficiency changes of hardware, and photosynthesis drives up, one must supplement the food for that otherwise ofc there will be a def. And P is needed for all cells and alot of enzymatic functions, too.

2com said:

And I've heard "strain dependent / genetic", but get the sense that's more of a copout when it can't be figured out (and from experience I've seen it go away, and fairly quickly, which made me think it was a mobile element mostly at play - hence the phosphorus "guess").

Click to expand...

Well, it seems to appear on sativa varieties more, these with thin-fingered blades and long but thin internodes.... these seem to have a lesser broad tolerance for high EC.. but never to the extent that a plant had this from beginning to end, rather one was able to actually observe that phenomenae.. whereas I haven't seen this on typical "indica"-structured plants.

this is an excellent writeup of how P behaves in soil and plants:
"31P-NMR studies reveal that the Pi efflux from the vacuole is insufficient to compensate for a rapid decrease of the cytosolic Pi concentration during P starvation (Pratt et al., 2009). "
this means that if something happens and the plant cannot "drink" enough P anymore, then the re-mobilization of P from its storage is NOT going to be enough to satisfy a plants demand (... and hitherto we see that metabolite buildup)

The article describes many reason why this can happen naturally in soil, plus any change in pH may also greatly affect this.

Kassiopeija said:

so what's your take on S, Fe & Mn?


I've read somewhere cannabis is a bor-sensitive plant, but this may be hear-say... I'm looking heavily at the micronute ratio from various plantfood and have found some conflicting info's on bor - it's either at the same level than manganese or around 25-50% of Mn.
The same can be said from Mn, which is sometimes even en parre with Fe, but most often ~~50% lower...

I'm finding very conflicting informations on the amount of Chlorine to use in Cannabis... found tissue sample concentrations can get extremely heavy - but that may be due to its abundancy in nature.
Both Na & Cl can both wreak havoc on the ion availability of other essentials.

Click to expand...

I'm really a dummy on micros. Have not looked into them. Prefer to just use whats in base nutes, and pray. Lol

I hear S is best late flower. Something about ripening or terps.

Lucas, h3ad and others for comparison.

TintEastwood said:

I hear S is best late flower. Something about ripening or terps.

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indeed, but would you choose calcium sulfate over epsom salt at that stage of a plants development? Or elementary S? Some of the sample tissue measurements shown suggest an increase of Mg in late flower to, sometimes, levels where Mg is en pare with Ca! And they did start out 2:1. So, that breaks pretty much by the genereally accepted 3:1.

But it's not getting into my brain why Ca should be that deplete when biomass acquisition is currently in order...? Outside in nature big plants roots hit the stoney region below the "mothersoil" sphere and get access to huge sources of it.

Kassiopeija said:

indeed, but would you choose calcium sulfate over epsom salt at that stage of a plants development? Or elementary S? Some of the sample tissue measurements shown suggest an increase of Mg in late flower to, sometimes, levels where Mg is en pare with Ca! And they did start out 2:1. So, that breaks pretty much by the genereally accepted 3:1.

But it's not getting into my brain why Ca should be that deplete when biomass acquisition is currently in order...? Outside in nature big plants roots hit the stoney region below the "mothersoil" sphere and get access to huge sources of it.

Click to expand...

I only have epsom for S.
Some reduce or elim Ca late flower.

Kassiopeija said:

so what's your take on S, Fe & Mn?


I've read somewhere cannabis is a bor-sensitive plant, but this may be hear-say... I'm looking heavily at the micronute ratio from various plantfood and have found some conflicting info's on bor - it's either at the same level than manganese or around 25-50% of Mn.
The same can be said from Mn, which is sometimes even en parre with Fe, but most often ~~50% lower...

I'm finding very conflicting informations on the amount of Chlorine to use in Cannabis... found tissue sample concentrations can get extremely heavy - but that may be due to its abundancy in nature.
Both Na & Cl can both wreak havoc on the ion availability of other essentials.

Click to expand...

I'm pretty new to all this, but I haven't been actively looking into much of the micronutrient side of things, mainly because there's little I can do about them. It's good you're looking into them.
Most of what I've heard is recent, and a fair amount is touched on in the three videos I listed above (among other sources that discussed the same things). Boron was brought up, I don't remember much other than it's general importance and sharing some similar deficiency symptoms with Potassium I think.

Kassiopeija said:

Well, it seems to appear on sativa varieties more, these with thin-fingered blades and long but thin internodes.... these seem to have a lesser broad tolerance for high EC.. but never to the extent that a plant had this from beginning to end, rather one was able to actually observe that phenomenae.. whereas I haven't seen this on typical "indica"-structured plants.

Click to expand...

I see it on nearly every plant that someone takes a photo or video of now. So much so that whenever I see a pic someone shared of their plants that are perfectly uniform green, I comment on how beautiful they look.
Thanks for sharing that, I'll try and warp my brain around some of it.

TintEastwood said:

Lucas, h3ad and others for comparison.

View attachment 4635233

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I get different number(s) from my calc, for jacks. The Ca is higher than the Mg, 120 : 91. And 230 for K.

I use jacks 3, 2, 1 but replaced his calcium with YaraLiva 15-0-0. At 100% strength my EC 2.0-2.2 thats before cal mag and silica. And dose Humic acid, fulvic acid, re-charge, tribus grow bacteria, then switch to bloom bacteria, Neptune's harvest 0-0-1, and a sugar nutrient like molasses, or sweet sticky once a week.