Jack's 10-30-20

Hey guys. I bought some Jack's 10-30-20 (have not received yet) with the intent of using for flower all the way through to harvest. Does anyone have any experience with using 10-30-20 all the way in flower? I would love to hear your thoughts, experience and input. Thanks!

i've been looking at jacks lately. i thought that formula is only for 2 weeks during transition?

the 15-5-20 is waht they list for flower

I wouldnt consider a ratio like 10-30-20 until mid-late flower, and only briefly, too much P

visajoe1 said:

I wouldnt consider a ratio like 10-30-20 until mid-late flower, and only briefly, too much P

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way too much IMO.

rkymtnman said:

i've been looking at jacks lately. i thought that formula is only for 2 weeks during transition?

the 15-5-20 is waht they list for flower

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I know that is what they say but they have so many products now that I do not remember seeing before. I only remember seeing the 321 until I looked again recently, saw this (132) and thought I would give it a try.

Bengfan said:

I know that is what they say but they have so many products now that I do not remember seeing before. I only remember seeing the 321 until I looked again recently, saw this (132) and thought I would give it a try.

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yeah, i think they are branching out to the weed grower finally.

i think the schedule i looked at was called the City Limits . for tap and well water (not RO)

amazon had 10 bags but they sold out of what they call Jack's Pro Tap

They are definitely starting to blend into the cannabis market.
I don't remember how I found this chart but I took a screenshot cuz I knew I would want to study it later.

i gave them a call today. they are back to work finally.

i scanned my well water analysis and sent it to tech support. they will look at it and provide a nute schedule.

pretty cool!

rkymtnman said:

i gave them a call today. they are back to work finally.

i scanned my well water analysis and sent it to tech support. they will look at it and provide a nute schedule.

pretty cool!

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That's awesome. If you would, please do post the results of what your H2O analysis was, and what their suggested nutrient regimen to offset the water is.

I use 1-3-2 jacks in flower and flower fuel and always get great results.

spek9 said:

That's awesome. If you would, please do post the results of what your H2O analysis was, and what their suggested nutrient regimen to offset the water is.

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i will try to remember that. i'll just start my own thread to not mess this one up. im guessing they have a backlog since they were gone from the office for awhile.

Bengfan said:

Hey guys. I bought some Jack's 10-30-20 (have not received yet) with the intent of using for flower all the way through to harvest. Does anyone have any experience with using 10-30-20 all the way in flower? I would love to hear your thoughts, experience and input. Thanks!

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I used it when I was starting out. I Was in dirt and I used it as a bloom booster in flower, seemed to work well. I wouldn't think just the 10 30 20 by itself would be good for all of flower. As stated, too much "P". I have been looking at Mel Frank's and Ed Rosenthal's numbers. They recommend more of 3-1-2 for veg and blend into a 1-1-2 for flower and even 0-1-2 late flower. This is my next plan of attack. Just giving my 2cents. Good luck. Let us know how it turns out.

Bengfan said:

Hey guys. I bought some Jack's 10-30-20 (have not received yet) with the intent of using for flower all the way through to harvest. Does anyone have any experience with using 10-30-20 all the way in flower? I would love to hear your thoughts, experience and input. Thanks!

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Back in the late 80's, when I first started growing I used the Peters (same brand) 10-30-20 for flower and their 20-20-20 for veg. It worked and I got good flower off the plants. I did that for a year or so before I had learned about pH and the GH Flora nutrients and hydroponics. After that I never looked back.

Knowing what I know now, that isn't the ideal ratios for growing what we grow, I was lucky my tap water had enough calcium and magnesium, and I was lucky that the peat based mix I had picked up at walmart ended up buffering the pH to something workable.

I really lucked out honestly lol. The flavor of the smoke and quality of the flower was amazing TBH. I had a bag seed Juicy Fruit plant (thats exactly what it smelled like) and it was amazing. Had a skunk strain that was also amazing and super stanky. When I switched to hydro the growth was faster and the yields improved and the flavor was even more intense and yummy.

Renfro said:

I used the Peters (same brand) 10-30-20 for flower and their 20-20-20 for veg

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have you heard of the dynamic duo with Peters? i guess it was before the 321 mix came out. it was a mix of the 10-30-20 and 202020. certain ratio for veg and then different for bloom.

Moabfighter said:

I use 1-3-2 jacks in flower and flower fuel and always get great results.
View attachment 4556361View attachment 4556360

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It is good to hear someone using 1-3-2. You did say you use it all the way through flower?

Bengfan said:

It is good to hear someone using 1-3-2. You did say you use it all the way through flower?

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and he also adds a 1-34-32 flower fuel too.
i'm a noob with NPK stuff but that seems not very good at all.
hope he publishes his feed schedule @Moabfighter .

rkymtnman said:

and he also adds a 1-34-32 flower fuel too.
i'm a noob with NPK stuff but that seems not very good at all.
hope he publishes his feed schedule @Moabfighter .

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Start with one q tsp and no flower fuel. Next week two q tsp. Repeat through six weeks. Then I back off on the jacks and go like 4 jacks 1 flower fuel 1 fox farms cha ching. Week 7 ish double the cha ching. Week 8/9 just distilled water.

it’s a easy schedule and it’s never held me back a lot I don’t think. I also use hydroguard and sometimes mammoth p but not always the mammoth.

edit and I add cal/mag once weekly. Not a huge fan of it though. Smells weird.

What works for me may not work for you though I don’t know?


jar of jacks buds..... seriously it’s about all I use in flower lol

I use jacks and I just use the part a and b with Epsom salt for the entire grow.

rkymtnman said:

have you heard of the dynamic duo with Peters? i guess it was before the 321 mix came out. it was a mix of the 10-30-20 and 202020. certain ratio for veg and then different for bloom.

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I looked into this a few months ago and considered going this route. I forget where I took the screen shot from.


For the record, neither Jack's All Purpose or Blossom Booster contain any cal/mag. However, Jack's Tomato Feed (12-15-30) which is relatively new has cal-mag. I think Jack's revised their original Dynamic Duo using the Tomato Feed in place of the All Purpose. This is from their site.