Jack’s Nutrients by JR Peters

Soluble. Available. Consistent.

Since 1947, these are the three words that you have come to expect when you open a bag of fertilizer made by the Peters’ Family — and now, the master-crafters at Jack’s introduce our small batch blends, Jack’s Nutrients: A collection of formulas that gives you choices that work for many different controlled environments without the hype or confusion of extravagant names and crazy labels.

Our Company

Welcome.  You have come to JR Peters Inc. to find the highest quality and truly soluble nutrients blends on the market.  How can we say that?  Because we are here watching over every step of the process.  From research and formulation design in our small batch lab, through the intense qualifying of the purest raw materials according to our QC standards, to our long time employees watching over each handcrafted batch on our blending lines.  The family at JR Peters ensures that the nutrients that are in our fertilizers, that you are giving to your plants, meet the strictest standards and will grow the highest quality plant material.

The Lab

Our onsite laboratory is the heart of our fertilizer family, the process always begins in the lab. What we have seen over the last few years is a great influx of people looking for some knowledge about how to get started with their operation without the confusion of consultants or hours spent on the web. From there we started focusing our hydroponic and cannabis growers to a testing program that helps them navigate how to get started growing.

Our Hydro Track and Nutrient Track programs are designed to be a tool kit of knowledge for a grower. Both new growers and those who have quite a bit of experience learn to understand what they are starting with in regards to their fertility.  These testing kits create a blueprint on how to grow your plants and what nutrients and additions you may need to use.  The technical support team at JR Peters then helps guide the grower to nutritional success.

Technical Support

We listen to you.  That’s right, we actually have real people here to listen and help you decide which formula is right for your growing environment.  Some say it’s as easy as ABC or 123 but we know that it’s not.  Our highly trained and personalized technical staff will answer your questions and walk you through everything you need to know from result interpretation from our onsite lab, to formula choice and to mixing advice.


How to grow with Jack’s?

The research team at JR Peters listened to their growers and designed a suite of formulas that provide results without the complications of multiple timed feeding schedules and additions.  Now, let’s figure out which formula’s are right for your grow.

Jack’s Nutrient Kits

A great way to get started or trial Jack’s products. Each kit contains:

  • A Grow formula specific to your water type

  • A Bloom formula to use during the correct timing of lighting switch and flowering

  • A starter formula so that you establish strong branched roots right from the clone stage

  • A finisher formula – strengthens and optimized the plants nutrients for maximum harvest

  • Each formula is in a 1 Kg (2.2 lbs) Ziptop pouch with mix instructions and nutrition schedule

  • All packed into a plastic bucket for mixing concentrated or dilute solutions

In addition, each formula is designed with specific micronutrient packages and powerful N P K ratios in order to optimize cannabis in the most efficient way.  Both extremely soluble and consistent, each batch of Jack’s reflects the perfect chemistry, matched to your water type and environment without all the hype and crazy labels that can distract from the science.

Let us help you decide what is the best kit for you. Our highly trained technical staff will answer your questions and walk you through everything you need to know to find the right kit for your plants and environment.  

All Kits Include…

Feeding Schedules



What is #Jacks321? Have you read about Jack’s 321 or seen the hashtag on insta?

Jack’s 321 is our tried and true two-part fertilizer program. It consists of Jack’s Nutrients Part A  5-12-26, Jack’s Nutrients Part B 15-0-0  and Epsom Salts. BUT where does that “321” come from, you ask? It’s the shortened amount of each fertilizer in grams per gallon.

To mix up the perfect blend of Jack’s 321 you will need:

 3.6 grams Part A (5-12-26)

 2.4 grams Part B (15-0-0)

1.1 grams of Epsom salts

This will give you a blend of nutrients for growing almost any controlled environment crop, in any growing system. The order of additions is VERY important. You must add the 5-12-26 first and make sure it is completely dissolved, then add in the Epsom salts making sure it is completely dissolved, then finally the calcium nitrate.

18 Replies to “Jack’s Nutrients by JR Peters”

  1. Tarell says:

    Hi how are you doing today. I was curious about the 5-12-26 is this used for veg or bloom? I see the middle number higher than the first, i also see your products from different growers on Instagram. I am a licensed grower and would like to try your product but i don’t know if it can be used with tap water, i only see other’s with RO water.if so which products do i choose? Thanks for taking the time to read this message.

    1. This is a three-part nutrient, with the second part being Calcium Nitrate. For more information check out our Feeding Schedule page.

  2. Steven says:

    Do you use the 321 ratio from seed to flower?

    1. The 3-2-1 is honestly more of a ratio than a recipe. So if you follow that rule you should be OK. Most people start at 1/4 strength, then 1/2 strength, etc.

  3. Jeff Edwards says:

    I’ve been using for Jack’s 321 for several years now. I stared out using “bottled nutrients”… all I can say is HOLY COW!
    My plants never looked so good! The customer service of JR Peters is second to none… period.
    If you are looking to up your game, look no further than JR Peters fertilizers for unmatched quality and the most explosive growth with your harvest!
    AsK for Dan Gillespie… he is the Grow Ninja at JR Peters.
    Thank you Dan!
    Jeff E.

  4. Dan Reese says:

    What ph water should I start with for the 321 system

    1. Starting pH is kind of irrelevant. Tap or RO water is recommended. Once the fertilizer is mixed THEN you can adjust the pH. I have had a few customers over the years pH the water before adding nutrients, this is not necessary and if anything can negatively effect the nutrients final pH reading as you have caused an imbalance.

  5. John Hulsey says:

    Can I mix Sprat- N-Grow with Jacks classic Blossom Booster both liquid forms mixed ???

    1. I don’t know explicitly, however i would error on the side of caution and spray these items on different day, typically at least 3 days apart. I hope that helps.

  6. Chris says:

    Looking to start using your product,need to have nutrients for veg and flower . I am using pro mix soil and tap water but I have a water softener can you point me in the right direction?

    1. Typically customers in soilless mediums use the 3-2-1 feeding schedule HERE

  7. Stephanie says:

    Are you supposed to eliminate the Part and A & B during the first two weeks of flower?

    1. If you use their 3 part system you do not need to use any other products during the first few weeks of bloom. Jack’s does have a “Bloom” formula that is a combination of the Jack’s A & B.

  8. J.E. PEREZ Jr says:

    I want to get on the 321 team with my soil but its alot easier to use my dechlorinated hose water. Does that change the 321 formula?

    1. Nope. Should work fine.

  9. J.E. PEREZ Jr says:

    So RO isnt required? Of course I know it’s always better to use RO water. Dechlorinated water out of my hose is just ALOT quicker then using my RO system connected to my kitchen sink.

  10. Ken Syers says:

    I’m using your product and sometimes when I mix a batch of nutrients in high concentrations I get a thick cloudy white sediment? What am I doing wrong?

    1. I have had so customer tell me they add the Calcium Nitrate first, then the Hydroponic Special, then Epsom Salt.

      The feeding schedule over at Jack’s Nutrients have been modified over the years and might help out as a guideline in the future.

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