Ponder me this

[Auggie]

I use Jacks Formula for plant feed.
A&B 40/60 ratio at 1100 ppm.
For bud set I use Jacks Bloom 10-30-20 with epsom salts to 900 ppm.

For last two weeks I use none of the B (nitrogen) and A only (P&K) and I add two ounces of MOAB and epsom salts of course to 1000 ppm.

So, here's my question:
Since Jacks A is P&K, does it really do me any good to spend the extra $ on MOAB?

One of the reasons I use Jacks is because I can spend $500 on feed -- FOR THE YEAR.
MOAB is freakin expensive -- and I don't mind spending the money if it's worth it.

My question is ... am I using MOAB right?

 

[013]

Soil guy so I don’t have a clue and there are so many variables from one grower to the next. The only way to really gauge this is to run a pair of clones identical and let the MOAB be the only difference to see results. Never used MOAB but if it’s just PK well... cheaper is just around the corner

 

[Redcup]

You do not need the MOAB, 0–52-32. You dont need such a large PK boost, since you are already feeding only Jacks hydro 5-12-27.

BTW It is just Mono Potassium Phosphate MKP. The label says it includes ammonium phosphate also, but given the NPK with 0 nitrogen it must be an inconsequential amount. You can purchase MKP directly by the pound on amazon for five bucks or so. If you really want it. Note that the Jacks has MPK as one of the salts.

i use a similar formula schedule as you, my tap water is hard and i use 1:1 ratio of Part A to B In veg. Then in bloom phase out the part b calcium nitrate, first 2:1 after stretch, then no B, as you do. it is a good regime. Cannabis needs less calcium as cell growth slows, and by late bloom it has taken up all the N it needs.

 

[Weaselcracker]

Auggie IMO there are no nutrients that are worth paying very much money for. They’re all available for cheap in bulk once you figure out what the base elements are and how to mix them.

Redcup it would be interesting to see you on Skybound’s nutrient mix thread Making Your Own Nutrient Concentrates and hear your thoughts. I’d never heard of or considered plants using less calcium in late flower.

There’s one clone I’ve been growing for the last five years that always goes for shit in mid or late flowering. Whatever it’s special needs are- I think they must be solvable. I’m gonna do side-by-side grows with it using different nutrient mixes- just scratching my head over what variations to try first.

 

[Redcup]

Weaselcracker thanks for the link, I will take a look.

About the Ca needs, its interesting. Does cannabis’ calcium requirement decrease in late flower? It makes sense on one level, calcium is used mainly for cell wall growth and repair, that activity decreases late in flower as foliage growth slows and leaves enter senescence, and secondary metabolites dont have Ca. That an oversimplification, calcium has other roles in metabolism, and so on.

Also, in coco, the cec sites must get saturated at some point and quit immobilizing Ca, it seems to me.

In terms of the NPK-Ca ratio, increasing the PK decreases the relative amount of Ca in the feed solution. So in that relative sense the needs go down but of course in absolute terms the plant still needs 180ppm of Ca through flower (or whatever is appropriate for a near 1:1 ratio of N:Ca). At 1000 ppm feed, thats 18% Ca; at 1800 ppm feed, with much more PK and the same Ca, thats 10% Ca.

As an example,
A quick glance at the GH flora feed 12 wk schedule shows the following: the calcium comes from Calimagic with 5% Ca and Floramicro, mostly cal nitrate with Ca 5%. they cut the calmag in half in wk 10, eliminate it in wk 11 and 12; they cut the micro in half in week 11 and eliminate it in week 12. So they are providing decreasing Ca at the end.

Also i have hard water, providing about 75ppm of Ca. I can use Jacks part A 5-12-26 without any Part B calcium nitrate, as high as 1.5 g/L (i guess thats about 800 uS ec) and still thats a 1:1 N to Ca ratio. So i am cutting Ca no more aggressively than the GH formula. Thats just a comparison.

I have run the Jacks at 1:1 part a:b and also 1.5:1 (ie jacks 321), using the same formula through the whole run, and also tried varying it as i described. To be honest I havent seen a big change of performance in any of the the recipe schedules. I’m not fixed to this feed schedule and if someone told be it doesnt meet the plants needs or that my plant physiology understand is nonsense, i wouldn’t be totally shocked lol. Ive only made about 8 runs of 2-4 plants with jacks in the last couple years, so its a small amount of data. Before that i used other products. The 1:1 ratio is recommended in a paper i read, maybe from cornell. The 321 is recommended on the Jack site.

Well I dont want to steal the thread and make it about me and calcium but I wanted to provide some detail so it doesnt sound like i am proposing to cut the calcium completely out in flower or something too kooky. And, the thread title says to ponder

The more unclear question with moab, is: does a plant benefit from high levels of P (anything over 60ppm) and if so, when should it be applied.

 

[Weaselcracker]

Thanks a lot for that.
These plants seem pretty tolerant of a range of different mixes/screwups , that’s for sure. Except for the occasional b**ch who almost never seems to be happy, which in my case is a Pineapple Chunk pheno which is hell to grow but for some reason produces my best smoke.

Side by side grow tests, are a bit of a pain in the ass. but can show things a lot more clearly than the usual ‘try it one way, then try it another way’ method. I have a feeling I’ll have to bite the bullet and try some clones with different mixes.
It’s really only the last month or so of flowering that concerns me most so it shouldn’t be all that big of a commitment. I use Hydro Buddy to calculate the mixes.

I don’t want to hijack the thread either but I’m asking myself the same question the OP is. Basically- whether to boost the ratio of P and K in late flowering.

Auggie if I get time I’ll enter the MOAB guaranteed analysis into the app to get an idea what it looks like- will get back to you if I do.

 

[Redcup]

The fertilizer solver looks like a fun tool you are playing with. Lets see if it comes out to be
0.96 * MKP 0-52-34
0.04 * MAP 12-61-0
= MOAB 0-52-32

So 96% MKP...Thats about one tsp MAP per cup of MKP

 

[013]

what is ppm’s?

Rhetorical question... I draw a gallon of water, slap in some kelp, splash of super thrive, few spoons of diatomaceous earth, 1/2 cup of unicorn poop, big squirt of fish guts, spoon or two of rock dust, little sulfur powder for good measure, maybe a spit of tobacco juice - stir that mother up with 9600 rpms on a paddle drill-bit. dip a meter in there to check ppms and the displays flashes “RUN“ - its fucking quicksand!

goop so thick I can slather it on with a trowel.... it’s not ppms at that point it’s parts per thousand and the plants don’t give a shit.

I know many growers do live by ppms tho.... and for hydro it’s of considerable importance - just saying there are many ways to get ‘er done

but damn redcup - that’s a helluva write up!

 

[Auggie]

just saying there are many ways to get ‘er done

Yes. I been saying this for years.
There are many ways to grow and enjoy this plant we love.
Few of them are the 'wrong' way.

I know a guy that truly is a master grower - I swear he could grow in concrete ... he doesn't measure anything ... just pours a couple glugs of this, and a splash of that and a pinch ... no wait, two pinches of this and ... done.

Side by side grow tests, are a bit of a pain in the ass. but can show things a lot more clearly than the usual

I actually plant one light ... nine plants in a 200+ plant room with my 'experiments.' Different feed, different medium ... usually the same genetic as the rest of the room.
Once I hung a new Gavita LED panel over them as a test.

Auggie IMO there are no nutrients that are worth paying very much money for. They’re all available for cheap in bulk once you figure out what the base elements are and how to mix them.

I am coming to the same conclusion.

 

[ZeroTolerance]

For what it's worth I also run jacks (31 ratio, 3.6:2.4:1.2 g/gal) and usually add 1g/gallon of monopotassium phosphate in bloom. I've also tried adding that 4% monoammonium phosphate to mimic MOAB, but (shockingly) didn't see any difference.

My current run is in smaller pots than I usually run and the plants burn easily, so I'm not using MKP. So far I haven't seen any noticeable differences in stretch, bud stacking, or leaf color.

The way I see it you really only need to provide the plants what they need in terms of nutrients, not anything more. If you have good light levels and temps / RH then the plant is going to grow healthy as long as there are enough nutrients. Jack's 31 provides (as far as I know) all the necessary nutrients at the right levels, so bloom boosters shouldn't be needed.

 

[013]

sounds like doc...

 

[Auggie]

Jack's 31 provides (as far as I know) all the necessary nutrients at the right levels, so bloom boosters shouldn't be needed.

That's kind of where I am arriving.
But, you know how it is: No matter HOW good the harvest, we're always thinking of ways to do it better. Just a little bit better.
And, that's good I guess.

The only thing I add to the 31 program is Shooting Powder as directed with carb, water soluble sea kelp with fulmic, and silica last three weeks.
I consistently get 1.2 to 1.3 grams per watt.
Once I went to 1.4 .... wish I knew how.