Jacks 3-2-1 Info

So I have some questions about the Jacks 3-2-1 mix and I figured just start a thread so everyone can refer to it in future since it is becoming so widely used.

Question #1. Is there a specific time I wanna ph? Do I ph water first ,or do I just mix part A qnd then part B then together and then ph?

Question #2. I’ve read its crucial to mix the 5-12-26 and the Epson (part A) first and to make sure it completely dissolves before adding part B and have also read its a bit of a chore to dissolve part A, my question is can I slightly heat my water before adding the 5-12-26 and the Epson to help it dissolve quicker or will that create a super saturated solution that I dont want and somehow give me an undesired outcome?

Question #3. In cocoa do I need to add a cal-mag supplement or does the Jacks provide the required amounts i need?

Question #4. Is the Jacks powder harmful health wise in regards to any dust encountered when mixing or measuring? Should I treat it like it has Covid and strap on the mask or is it harmless as long as your not cutting lines and sniffing them?

Question #5. Is silica essential or is it considered a supplement ,and if not essential how will its use help my yeild or overall plant health or harm if not used?

Hope those make sense and if answerable, can help out someone else aswell as myself!
Thanks ahead of time to any and all answers ,opinions, general knowledge!


I’ll follow if ua don’t mind im looking to switch to jacks as well my self


Of course ,all are welcome!

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Tagging a few I know are using Jacks or other dry nutes

@DefNSmokn @imSICKkid @Nicky @Covertgrower @CoyoteCody @Not2SureYet @Holmes @Hellraiser @AfgVet @repins12


You should always mix then ph I doubt heating it will cause a problem(as long as it’s close to room temp when feeding ) , extra calmag probably wouldnt hurt either it’s pretty hard to overdue calmag in coco, silica isnt absolutely necessary but it does add structural support and healthy growth so better to have it


Mix part A and epsom together first, then part B. Always in this order. Mixing the three all at the same time causes it to clump together, making it non dissolvable.

You could, but seems unnecessary. For the rest, see
answer 1.

The recipe includes calcium. A lot of it. This is unnecessary.

I wouldn’t do any lines with it, but using common sense also goes here.

Silica is a supplement. It’s literally one of the most common elements on the planet. It’s everywhere.


Everything that Covert said. Just ph your solution after you have mixed it all up.


Covert has you covered.


@Covertgrower ill remember to tag you when I have chemical questions. I went thru this two days ago when adding powered nutes to hydro setup…Literally freaked and dumped a days worth of water in order to redo it with liquid cal/mag instead of magnesium sulfate and calcium nitrate, I read it creates calcium sulfate and wasn’t sure how that would affect the plants… think I just got a bachelors in science after the reading I’ve done :wink:

Probably not because I’d need to comprehend the material

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Happy to help where I can. @PharmerBob


Timing is EVERYTHING. literally 5 minutes before i read this post i opened my order of Jack’s that arrived last night. i was so excited until the realization hit “omg, now what do i do? how do i mix this? i remember seeing some posts about it”
I sat at the computer, looked at my ILGM forum (always up) and this was the first post that i saw. Thanks @Kotnmouf for the excellent (and very timely) questions and of course @Covertgrower for laying out the responses so even a newbie like me can follow along.
Although it seems some days like i am trying my best to wipe out my current grow, TODAY WILL NOT BE THAT DAY. well, not cause i poisoned them with incorrectly mixed nutes at least.


Warm water will help it dissolve faster. But if you’re using tap water, make sure to heat the cold water on a stove or microwave. Running warm water out of your faucet can cause the water to pick up more minerals from your water heater making your ppm’s rise.


And per gallon:

3.6 g Part A
2.4 g Part B
1.2 G Epsom


Lots of advice from the team here, :+1:


Been using Jacks for a few months now.
I just use room temp water.
Add part A and mix for a minute, then I the epsom salt…
at this point I just go do something else for a few minutes.
Theres always something to clean up , trim, organize, write down, burp, or just look at.
Then go back and shake up the mix again before adding part B.
I only mix a gallon at a time and I dont weigh the product.
1/2 tsp part A
1/4 tsp epsom
1/2 tsp part B
For me this mix needs 1ml pH down and it lands at 6.5-6.6 ph
Its not a real finicky system.
If you start to see some nute burn just water with plain pH’d water a time or two and let the plant use up the excess nutes.


How true. Also, we only soften our hot water. PPM between hot vs cold water makes a big difference.


Thank you very much for your timely and thorough reply!

One more question , Is it ok to start jacks when already say in week 2 with other nutes? Will i sho k the plant or cause any other unwanted effects?

Thank you everyone, as I expected this has already helped numerous people!

Apologies I missed your response. I would drop the other nutrient line, then start jacks immediately on you next scheduled feeding.
You should be good to go. When I switched, I noticed an immediate difference within 2 days.

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@Myfriendis410 @Covertgrower I am checking out Jack’s too and Greenjenes included .8g of soluble fulvic acid (reference: Jacks Hydro Tutorial from 2016 - YouTube )
Not necessary in your opinion? I would also want to include humic acid - that’s just me.

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