I dont remember. I’m still on the bags I bought 2 years ago. Bought the big ones from amazon
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Hey, welcome to OG.
I’ve been using 321 for years, with an “old” formulation of Jack’s.
You’re correct in that it has “always” been 3.6/2.4/1.2, but has changed to 1.1g on MgSO4 (epsom) - the reasoning for this, I believe, is Jack’s increased the base Magnesium in their latest Part A (5-12-26) formulation, thus less Mg needed to supplement.
They have a TON of magnesium in general in Part A (6.3% or so!) which I think is overkill.
In the end, 3.6/2.4/1.1 will work really well as a plug and play mix for growing - I’ve had amazing success with it, it’s “cheap” (compared to bottled etc), and it just works.
Having said that, the assumptions Jack’s makes in the Part A I don’t feel are greatly tuned for cannabis, and their increasingly complex feed schedule incorporating more of their nutrients such as “bloom” is starting to turn me off. I just don’t feel great about being reliant on nutrient products.
I’ve been talking with @lefthandseeds a lot about this as he’s very well read on nutrient interactions and we’re building out a fully custom mix from base nutrients that will reach perfect PPM levels for hydroponic cannabis. I’m hoping we get it to the point that I can “replicate” jack’s with a single part A mix, and the same addon of Cal Nitrate and Mg.
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I feel jacks was better when it was Peters Pro Hydroponic….but still works amazingly well!!
I agree about the Magnesium…that’s why I only add in a additional 30 ppm…
As far as the bloom booster goes you should be using it the first week or two of 12/12 to force the plants into flower faster with less stretch and closer node spacing…some refer to this as crop steering…I actually use the 5-50-18 “Ultraviolet” for the first week…then 10-30-20 depending on strain!
I used without a booster for well over ten years and can tell you it’s a great addition and makes a hell of a difference in the product….
Also the high Potassium “Finish” is a must have….
Alaskagrown
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Do you have any comments or insight on the 2021 cannabis feed schedule values of 3.8 - 2.5 - 1.0 for 321? Has someone made a spreadsheet of the elemental ppm breakdown showing what that looks like compared to 3.6 - 2.4 - 1.1 elsewhere? I still have yet to receive a response from the company on this question.
I’ve never seen the 3.8* ratio mentioned before. Since I’m on the old formulation still, I run 3.6/2.4/1.2 and it’s been great. The only issues I’ve had in grows have been entirely my fault.
Have you ever tried Hydro Buddy? It might take some fiddling to figure out but that tool can do all kinds of calculations.
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+1 on the Hydrobuddy…amazing spreadsheet based nutrient calculator! 
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I haven’t seen discussion of this elsewhere either. Perhaps the intention is that 3.6 - 2.4 - 1.1 is the one ratio if you just want to use 321 for all stages without thinking too hard and this 3.8 - 2.5 - 1.0 is the precise recommendation for these particular stages if you are also using the Clone, Bloom and Finish products? In this video they show their 2020 cannabis feed schedule and they print it out as 378.54 - 252.36 - 98.94 grams per 100 gallons.
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To throw a wrench in the works alot run a more dilute 3g/2g/1g ratio which is approx 80% of listed.
Also due to the high mag content in the base some are happy using just a 4g/2g ratio with no epsom
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I do this ………… check out my journal 1st time growing and used Jack’s
Look at it like this (3.6 , 2.4, 1.2) is 100% (full strength)
If you start seeing tips burning bump it down a little like this….
Instead of running 100% bump it down to 90%.
If your digital scale won’t do these calculations round 
Or 
3.6 X 90% = 3.24 or. 3.2
2.4 X 90% = 2.16. Or. 2.2
1.2 X 90% = 1.08. Or. 1.1 ect
You can fine tweak it like this ,
If you need to bump it down to 85%,87%, ect…… just plug in that formula for the percentage of Jack’s you want to dial down to until your plants are happy. Hope this helps .
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I mix full strength and then just dilute down to my desired EC with a meter. In this case I’m not concerned about how many grams of the three parts I should mix in total to reach an EC, I’m only concerned with what the official recommended ratio of the three parts is considered to be the most optimal for cannabis by JR Peters. There is endless discussion on the net about whether 321 has too much/little of this or that so I’m wondering if they are tweaking the official ratio in these feedcharts.
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I’ve spent 13 yrs doing my research before I did my first run, I didn’t want to be one that started a run and ran into all the newb mistakes.
Also if you see my name Fat Man it’s in regards to a famous guy on rollitup up, ICMAG, thcfarmer named Fat Man he had a “nutrient salts “ thread and was a damn near genius or chemist or something but this was like 15-20 years ago. You can still read his threads today. I started reading them like 5 years ago. Anyways hope this helps
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Do what ever you want that’s what works for me.
For the record I’ve always mixed up my Jacks by ppm not weight and at a 1:.67 or 1:.6 ratio
On a 700 scale Hanna
800 ppm part A
30-50ppm Epsom
540 ppm part B(Technically 536 ppm)
1370-1390 ppm total solution
Alaskagrown
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What kind of lights/medium/fert frequency are you running in your setup? That’s a Lotta juice lol
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Welcome to Overgrow @Coconutz
Currently using 315 CMH, Hortilux Ceramic HPS for lighting…
I’ve used this same formula for Aeroponics, DWC, Coco/Peat moss in fabric pots, top feed drain to waste, ebb & flow…in every situation with great results.
The flood tables are filled with coco chunks…they get fed three times a day.
Small tester clones of Death by Terps and FPOG
Alaskagrown
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Regarding what is considered the current recommended mixing rates, I received this information from Jack’s:
"So originally the 3-2-1 started out as mixing Part A 3 g/gal, Part B 2 g/gal, and Epsom salt 1 g/gal. From there, we recalculated the 3-2-1 in order to increase the total EC and mixing rates which was: Part A 3.6 g/gal, Part B 2.4 g/gal, and Epsom salt 1.1 g/gal. Now the most current and up to date mixing rates are: Part A 3.78 g/gal, Part B 2.52 g/gal, and Epsom salt 0.98 g/gal - these mixing rates are designed for exactly 3.78 liters of water or 1 gallon of water. These are the same mixing rates you will find on our grow schedules and the mixing rates we recommend to use when applying Part A, Part B, & Epsom salts.
…we have nutrient solution target ranges designed for cannabis and for each life stage (target ranges attached). Originally, the 3-2-1 came from growers mixing part A, part B, and Epsom salts at a 3:2:1 ratio and this became very popular. A few years later, we re calculated the mixing rates to 3.6, 2.4, & 1.1, in order to get growers more in the middle of our target ranges for cannabis. Then about a year ago, we re calculated the 3-2-1 again for mixing into 3.78 liters of water exactly. This resulted in the mixing rates changing to: 3.78, 2.52, and 0.98 per 3.78 liters of water.
If you are still using 3.6, 2.4, and 1.1 of Epsom salts - this is totally fine and you will not find a huge difference between the most up to date mixing rates and as far as elemental ppm differences. The most up to date mixing rates are 3.78, 2.52, and 0.98 Epsom salts and this should result in a final EC of 2.0 - 2.4."
They also included the following charts:
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Did all nutrient lines jack up their price in the past couple years? I bought a 25lb bag of Jack’s 15-12-26 a few years ago for $80 shipped. Now it costs $140 shipped. I haven’t needed to re-supply but will probably need to some time next year
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Double whammy of inflation and sanctions… the money supply is 30% higher than a few years ago and prices are just catching up, plus there’s a lot of fertilizer that was previously coming from Russia and isn’t anymore. It was the largest exporter in the world a few months ago.
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Do any of you alter the ratio during flower? I’ve been cutting back the Cal-Nit and increasing the Epson after week 5-6.
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I’m running Jack’s 5-12-26 with CalciNit. Can anyone give me recommendations on what I can do to compensate for my tap water’s ppm levels besides cutting it with RO water? This is what the local municipal water treatment plant’s report says about my water:
Chloride = 93.9 ppm
Sulfate = 144 ppm
Total Dissolved Solids = 477 ppm
Sodium = 81.8 ppm
Alkalinity - Total as CaCO3 = 126ppm (Calcium Carbonate?)
When I run jack’s @ 600ppm indoor with my RO water my plants seem to turn out great. I have some plants outdoors running jack’s with tap water though and they seem to be lacking in yield even though they look very healthy. I suspect I may have too much nitrogen or calcium availability in my water? Using RO water for my outdoor plants isn’t an option because my outdoor plants drink a lot more water than my indoor plants and I cannot produce enough RO water for my outdoor plants. I would like to adapt to the tap water, if possible
Here is a thread I made documenting the lack of yield on my outdoor plants running jack’s+tap water