Only if you’re dropping N by using less calcium nitrate. The MB doesn’t have calcium, so it’s ok to reduce that, but you’re also going to be reducing your micronutrients. I used TM7 to add those back, but I’m not sure if you’ll have any problems from that.
I would check numbers in hydrobuddy but I need to know grams of each fertilizer.
I’ll break down and order a scale and get more precise with this. I’m just doing tsp cause it’s easy af to use. 2tsp of each, mix and water and they grow.
This is one of the most informative Jacks/321 threads I’ve came across in a while. I run 3/2.5 with 100 ppm of gypsum for veg and 3/2.5 with 100ppm of MPK for the flower room alternating Hypogrow and Drip Clean every res change. The 55 gallon res will last under two weeks, super stable with no ph fluctuations.
Jacks has made it lesser of hassle as far my nutes go. Great shelf life, economical and discreet. Good stuff coming out of Allentown, PA!
Interesting! I think I am currently experiencing the same thing with my sativa dominant plants. My medium to heavy feeders look great, but the sativa doms are clearly not happy, despite going fairly light on the nutes.
To be fair, I’ve been pretty sick and unable to keep up with things properly, but even so I am not used to seeing this wide a disparity in response between strains compared to previous regimens.
[Edited to add]
You can kind of see that in this pic, where the foreground plant looks decent (considering, anyways) but the plant in the background has leaves that look horrible.
Some of the more sativa plants have nice colors, but also a lot of really unhappy areas that are pale, blotchy, and “burnt”.
I thought this was a Jack’s 321 thread?
Well, I mean… From the very first post, and according to the thread title, it’s been about reengineering Jack’s 3-2-1 to better suit the needs of the op @lefthandseeds, so I imagine it’s a thread about whatever he says it is. 
You might be thinking of this thread?
Leeching off you gentlemens’ advanced knowledge of plants and their needs in coco coir, I’ve been nursing 2 lovely little plants (and two clones) to maturity with MB.
Now comes the time to spread their wings; I’m gonna flip the switch in a couple of days.
Now I know that altering the formula to use magnesium sulfate instead of magnesium nitrate is benificial, as the nitrogen is no longer heavily used by the plants - but do you use some kind of PK booster, or any other type of supplement?
I’m not personally a fan of the PK boost in coco. Coco already puts a lot of strain on your calcium and magnesium requirements and using PK, even for a week always seemed to put me into a calcium deficiency.
With the MB, if you get dark green foliage, I’d be interested to hear. It seemed to work pretty good for me on heavier feeding hybrid strains, but my pure sativas and Lebanese landraces really didn’t like the extra NH4 in the mix.
Well thats good news, no PK booster keeps it nice and simple. Might just make the switch to being a coco grower.
My plants look a very healthy shade of green atm, but they are hybdris (Big Bud & Super Kush).
They came out with a finish and bloom product which i used in my last grow and the plants came out amazing.
This was their response.
“Thanks for reaching out and choosing Jacks! The bloom formula was designed to help the plant transition into flower. However, our trial growers figured out to only use the bloom and Epsom first 2 weeks from flip and then switch back to the Part A/Part B and Epsom salts. Two weeks before harvest, we recommend using the finish formula which helps fatten up the buds.”
Anyone have experience with the RO specific Jack’s 12-4-16 in coco? Was wondering how it stacks up considering its a 1 part mix instead of the A and B.
Whoa, what a thread! Don’t think I’ve ever bookmarked so many posts in a single posting :). Your journey is a huge help as I start on my coco/dry ferts path. I admire your curiosity, perfectionism, passion and organization skills. Big thanks to you and everyone else contributing here 
!
The biggest break-through is probably the realization that all the ratios and calculations are based on elemental and not compound ppms. It’s a liberating nugget of knowledge, after that everything seems easy and a playground for ideas. Now to put all that knowledge in action and cement it in a protocol…
People pay for premixed nutrients is because the dry fertilizer companies like Jacks, Plant Prod, etc… never promoted to the retail hydrp market as they catered to farms/commercial food/ornamental grows. In that time the retail hydro manufacturers stepped in with fancy labels and lots of feed charts while also demonizing dry nutrients are not suitable for cannabis growing lol
I’m going to need some time to dig through your thread. I have a pretty simple coco regiment going. Gypsum really transformed my coco experience. Hahaha do your thing way too scientific for me I just kinda wing it.
That’s a really great feedback. Simple solutions are sometimes the best one. I think looking to rock dusts is not a bad approach in my opinion, because it’s hard to get calcium in salts without adding more nitrogen.
I don’t know much of the science of it. But since I started flushing with it weekly and adding it as a percentage of every feed. My work has been on point.
gypsum is neutral…would buffer…could add at the start as well perhaps? Have to make sure the pH is where you want before adding? Perhaps better at transition
5 gallon bucket of RO bubbling. Then I get a little warm tap water and mix 3 teaspoons Maxibloom 2 teaspoons diamond k solution grade gypsum. Usually ec is around 1200, then I ad 3.5ml of flora micro. And pH up to around 6.0
gypsum should help pick the terps up as well as improve the flower yield and quality. if done right.
I seriously use it start through flush. Only other things I ever use are epsom salts, cal nitrate, mag nitrate. Just because maxi has no N
