Jacks 321 vs Masterblend/Calnit/Epsom salt analysis

Hello everyone,
as someone that has been using Masterblend for years now with great results i decided to deep dive into the nutrient composition of both Masterblend and Jacks, both well known brands and i was wondering if anyone knows if theres any real difference between these two brands final recommended combinations, when i look at the nutrient breakdown on Jacks 5-12-26 formula:

and on Masterblends 4-18-38:

it seems like Jacks 5-12-26 is basically just Masterblends 4-18-38 with added magnesium sulfate, to the point where Masterblend has its own 5-12-26 product that is just the 4-18-38 + epsom salt premixed in it and looks almost exactly like Jack's:


since both these brands instruct the addition of the same amount of calcium nitrate theres nothing interesting there so i wont mention it going forward just assume i include it, what i do find interesting and where the differences show up is the addition of epsom salt (magnesium sulfate),

if you use Masterblends 4-18-38 they advise that you add epsom salt at a 2 to 1 ratio, for every 2 gram of masterblend 4-18-38 add 1 gram of epsom salt, or if you buy the premixed version of 5-12-26 you dont have to add anything besides the calcium nitrate,

on the other hand with jacks 321 setup, you start with the 5-12-26 that already has magnesium sulfate in it much like the premixed 5-12-26 masterblend only jacks has a tad more magnesium sulfate 6.3%/8.5% vs masterblend 4.1%/5.4% and on top of this they tell you to add even more magnesium sulfate at a ratio of 3 to 1.

So which formulation has it right? should i be adding more magnesium sulfate to my Masterblend 5-12-26 formulation similar to the Jack's ratio? and since the 5-12-26 formulation is just the 4-18-38 with added magnesium sulfate at a 2 to 1 ratio does this mean that the touted 12g/12g/6g per 5gal of water that MPHgardener made so popular on youtube all those years ago should have actually been 12g/12g/12g per 5gal? or am i just not reading this properly and its actually the same for both brands?

thanks

PS: both these brands recommend a ph between 6.4 and 6.7 and yet i've been told again and again that cannabis needs 5.8 or no higher then 6, any thoughts on this?

They're all pretty similar and all will grow good weed. I've been thinking of trying the Masterblend 5-11-26. What I'm currently using is 3-10-20 and I add calcium nitrate. But after years of trouble free grows I'm reluctant to change things up.

5-11-26 Hydroponic Formula Guaranteed Analysis

Dreddd said:

PS: both these brands recommend a ph between 6.4 and 6.7 and yet i've been told again and again that cannabis needs 5.8 or no higher then 6, any thoughts on this?

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Coco is 5.8 thru 6.2.
Soil 6.4 thru 6.7 is common.

TintEastwood said:

Coco is 5.8 thru 6.2.
Soil 6.4 thru 6.7 is common.

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im actually growing in DWC mostly so even though both companies say to 6.4-6.7 regarless of method i should be aiming at 5.8?

xtsho said:

They're all pretty similar and all will grow good weed. I've been thinking of trying the Masterblend 5-11-26. What I'm currently using is 3-10-20 and I add calcium nitrate. But after years of trouble free grows I'm reluctant to change things up.

5-11-26 Hydroponic Formula Guaranteed Analysis

Total Nitrogen (N) 5% Nitrate Nitrogen	5%
Available Phosphate (P2O5)	11%
Soluble Potash (K2O)	26%
Magnesium (Mg) (Total) 3.11% Water Soluble Magnesium (Mg)	3.11%
Sulfur (S)	4%
Boron (B)	0.05%
Copper (Cu) 0.015% Chelated Copper (Cu)	0.015%
Iron (Fe) 0.30% Chelated Iron (Fe)	0.30%
Manganese (Mn) 0.05% Chelated Manganese (Mn)	0.05%
Molybdenum (Mo	0.01%
Zinc (Zn) 0.015% Chelated Zinc (Zn)	0.015%

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i know what you mean.. im using the original masterblend at 2-2-1 with calnit/epsom and shit just works.. i was just curious about the extra mag in jacks.

Dreddd said:

im actually growing in DWC mostly so even though both companies say to 6.4-6.7 regarless of method i should be aiming at 5.8?

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I've always ran 6.0 in coco, flood and drain, and DWC.

I run Masterblend, calnit and mag at the recommended 2.4g, 2.4g, 1.2g. in veg. In flower I ran 2.4g, 2.4g, 2.4g. Just recently I lowered the mag down to 1.8g. The plants seem to like the lower amount of mag for some reason.

I can't imagine having better plants then I do with this formula. I was considering switching to Jacks a little while back but thought better of it. No real reason to. MB is cheaper and a lot easier to come by.

As for pH; I have been running an abnormal 6.4 in coco for the past couple years. Done a lot of reading over the years on this site about better calcium uptake at a higher pH. I have never had better, healthier plants in my life.

NeWcS said:

I run Masterblend, calnit and mag at the recommended 2.4g, 2.4g, 1.2g. in veg. In flower I ran 2.4g, 2.4g, 2.4g. Just recently I lowered the mag down to 1.8g. The plants seem to like the lower amount of mag for some reason.

I can't imagine having better plants then I do with this formula. I was considering switching to Jacks a little while back but thought better of it. No real reason to. MB is cheaper and a lot easier to come by.

As for pH; I have been running an abnormal 6.4 in coco for the past couple years. Done a lot of reading over the years on this site about better calcium uptake at a higher pH. I have never had better, healthier plants in my life.

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thats great to hear man, i also move up the mag from the usual 12/12/6 i used since forever to 12/12/8 in flower, interesting about the ph, so staying under 6 really isnt that critical huh..?

Coco/perlite.
Fwiw...I vary it from 5.9 thru 6.3. 6.2 mostly. Jacks or Mega nutes.

@ 5.8 I had more issues.

Dreddd said:

thats great to hear man, i also move up the mag from the usual 12/12/6 i used since forever to 12/12/8 in flower, interesting about the ph, so staying under 6 really isnt that critical huh..?

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I'm not certain that pH has the power we all were taught. I think it's more about consistency then it does a number. Idk. When I mix a new 25gal reservoir it's settles at 6.4 on its own. I don't mess with it unless it drops below 5.8.

I think the same about npk. As growers we were taught that the npk matters. However, looking at masterblend, jacks, megacrap, or any of the other 100s of schedules out there we can see the npk doesn't matter that much. Between all those brands and mixing and matching products we never have a balanced npk. My seedling to flower plants get the same thing(npk). ~Proof that having a veg and flower nute might not be needed and just marketing. Running the same formula from start to finish helps illustrate this. Idk I'm rambling.

I'm still learning about this stuff.

Dreddd said:

when i look at the nutrient breakdown on Jacks 5-12-26 formula

Click to expand...

one thing that is better about Jack's is that it's N is all from nitrate while Masterblend has 0.5% ammonia as it's N mix (cheaper source of N)

NeWcS said:

I'm not certain that pH has the power we all were taught. I think it's more about consistency then it does a number. Idk.

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Incorrect. All nutrients have an 'uptake window', whereby if the pH is too low or too high, that nutrient can no longer be uptaken by the plant, causing an artificial nutrient deficiency situation. You can add as much of that nutrient as you want, but if your pH is out of range, you're causing a toxicity situation within the medium while your plant can't use it. Each medium type requires a different pH range for maximum uptake of each nutrient.

NeWcS said:

I think the same about npk. As growers we were taught that the npk matters. However, looking at masterblend, jacks, megacrap, or any of the other 100s of schedules out there we can see the npk doesn't matter that much.

Click to expand...

That's incorrect as well. For one example, too much Potassium (K) can begin locking out Nitrogen (N), Calcium (Ca) and Magnesium (Mg). The effect of having too much of one nutrient causing the others to be reduced in uptake is called "nutrient antagonism". It's very complex trying to perfectly balance everything, but if one thing is too far off, other things can suffer greatly.

rkymtnman said:

one thing that is better about Jack's is that it's N is all from nitrate while Masterblend has 0.5% ammonia as it's N mix (cheaper source of N)

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good to know although it probably makes very little difference as both mixes when combined as instructed get the majority of their nitrogen from calcium nitrate.

spek9 said:

Incorrect. All nutrients have an 'uptake window', whereby if the pH is too low or too high, that nutrient can no longer be uptaken by the plant, causing an artificial nutrient deficiency situation. You can add as much of that nutrient as you want, but if your pH is out of range, you're causing a toxicity situation within the medium while your plant can't use it. Each medium type requires a different pH range for maximum uptake of each nutrient.



That's incorrect as well. For one example, too much Potassium (K) can begin locking out Nitrogen (N), Calcium (Ca) and Magnesium (Mg). The effect of having too much of one nutrient causing the others to be reduced in uptake is called "nutrient antagonism". It's very complex trying to perfectly balance everything, but if one thing is too far off, other things can suffer greatly.

Click to expand...

when it comes to ph i know you're technically right but at the same time i really see no difference between growing with either jack or masterblend at a ph of 5.8 or 6.4, on paper this should make a big difference but in reality its pretty much unnoticeable, maybe if someone would do a side by side with the same genetics and only variance being the ph..

spek9 said:

Incorrect. All nutrients have an 'uptake window', whereby if the pH is too low or too high, that nutrient can no longer be uptaken by the plant, causing an artificial nutrient deficiency situation. You can add as much of that nutrient as you want, but if your pH is out of range, you're causing a toxicity situation within the medium while your plant can't use it. Each medium type requires a different pH range for maximum uptake of each nutrient.



That's incorrect as well. For one example, too much Potassium (K) can begin locking out Nitrogen (N), Calcium (Ca) and Magnesium (Mg). The effect of having too much of one nutrient causing the others to be reduced in uptake is called "nutrient antagonism". It's very complex trying to perfectly balance everything, but if one thing is too far off, other things can suffer greatly.

Click to expand...

Yes, I have read the book. I am not debating how pH works and how plants need a proper balance. I am saying I run my coco at a higher pH, based on discussion on this site, and my plants have never looked better. With that said; I am to think that the range we're told is an optimal 'window' for coco, may not be so. This is assuming you use the recommended 'hydro' scale from most online charts.

Anyways

TintEastwood said:

I'm still learning about this stuff.

View attachment 4588613

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See based on this we are told we should change things from veg to flower. I disagree. And this style of 'start to finish'(veg+bloom, masterblend, 321) nutes is making it more clear. I think veg+bloom may have been to first to market it. I'm sure I'm wrong. Lucas was a start to finish I believe too(and maxibloom).
I'll never go back
Npk+calnit+mag+silica=Done

NeWcS said:

See based on this we are told we should change things from veg to flower. I disagree. And this style of 'start to finish'(veg+bloom, masterblend, 321) nutes is making it more clear. I think veg+bloom may have been to first to market it. I'm sure I'm wrong. Lucas was a start to finish I believe too(and maxibloom).
I'll never go back
Npk+calnit+mag+silica=Done

Click to expand...

is silica something you notice a difference when you add it? i never bothered going beyond the basic npk+calnit+mag mix but im always looking to improve if i can.

Dreddd said:

is silica something you notice a difference when you add it? i never bothered going beyond the basic npk+calnit+mag mix but im always looking to improve if i can.

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I feel like I notice a difference. My leaves are tough as leather and very rigid.

The masterblend NPK with calnit is 20-18-38, that's good for veg.

But in flower that ratio is high in N, so the accepted practice is to replace or greatly reduce the calnit (15.5-0-0) in favor of monopotassium phosphate (0-52-34).

Phosphates like MKP are the main ingredient in all the fancy bloom booster bottles.

jph said:

The masterblend NPK with calnit is 20-18-38, that's good for veg.

But in flower that ratio is high in N, so the accepted practice is to replace or greatly reduce the calnit (15.5-0-0) in favor of monopotassium phosphate (0-52-34).

Phosphates like MKP are the main ingredient in all the fancy bloom booster bottles.

Click to expand...

Im actually in the process of ordering a 25kg bag of haifa MKP , but i thought it replaces some of the masterblend not the calnit...? even if nitrogen demands are lower it still needs calcium doesnt it? Masterblend on its own has none..