Different NPK ratio for different stages of flowering

Hi everyone, i would like to ask a question to the top growers here, but also share opinions about our experience: which NPK ratio do you think works the best for each phase of flowering? Meaning transition and stretch, then early budding, bud swelling, and ripening before an eventual flush?
And most importantly, how do you find the right proportion between phosphorus and potassium in the different stages? A lot of growers and nutrient companies suggest higher P than K, other growers claim the opposite.

Here’s what i’m experimenting with my coco grow, currently at the beginning of week 4 of flower:
NPK: 6.3-12-17.3
I am planning to give her progressively less nitrogen and phosphorus to get around
0-2-3 in the last 2 weeks before flush.
I’m trying new nutes and ratios this run. What do you think about those values?

If you got time to lose, here’s my feed chart for this week:
(5 ml= 1 pt)
GHE floraMicro 0.3 pt= 1.5-0-0.3 (1.5 ml)
GHE floraBloom 2 pt= 0-10-8 ( 10 ml)
AN Bigbud 2 pt= 0-2-6(10ml)
AN Budcandy 1 pt=0-0-1. (5 ml)
AN Nirvana 2 pt=0-0-2. (10ml)
AN Cmag+ 1,2 pt= 4.8-0-0 (6.ml)
Tot npk = 6.3-12-17.3
Tot ec (10 lt of 0 ppms h20)=380-400 ppms

This run i wanted to try AN and see if it’s really that expensive crap that many people claim it is, or it can make any minimal difference if used the right way.
I’ve always used basic and old schooled nutes like ghe, but this is not the topic.
Around the last weeks, I am planning to gradually switch to this:
Target NPK: 0-2-3

AN Overdrive: 0-2.5-2 0.5 pt

GHE FlBloom: 0-2.5-2 0.5 pt

AN Bigbud: 0-2.6-7.8 2.6pt

Tot NPK 0-7.6-12.8 (0-1.9-3.2)

giantcola said:

Hi everyone, i would like to ask a question to the top growers here, but also share opinions about our experience: which NPK ratio do you think works the best for each phase of flowering? Meaning transition and stretch, then early budding, bud swelling, and ripening before an eventual flush?
And most importantly, how do you find the right proportion between phosphorus and potassium in the different stages? A lot of growers and nutrient companies suggest higher P than K, other growers claim the opposite.

Here’s what i’m experimenting with my coco grow, currently at the beginning of week 4 of flower:
NPK: 6.3-12-17.3
I am planning to give her progressively less nitrogen and phosphorus to get around
0-2-3 in the last 2 weeks before flush.
I’m trying new nutes and ratios this run. What do you think about those values?

If you got time to lose, here’s my feed chart for this week:
(5 ml= 1 pt)
GHE floraMicro 0.3 pt= 1.5-0-0.3 (1.5 ml)
GHE floraBloom 2 pt= 0-10-8 ( 10 ml)
AN Bigbud 2 pt= 0-2-6(10ml)
AN Budcandy 1 pt=0-0-1. (5 ml)
AN Nirvana 2 pt=0-0-2. (10ml)
AN Cmag+ 1,2 pt= 4.8-0-0 (6.ml)
Tot npk = 6.3-12-17.3
Tot ec (10 lt of 0 ppms h20)=380-400 ppms

This run i wanted to try AN and see if it’s really that expensive crap that many people claim it is, or it can make any minimal difference if used the right way.
I’ve always used basic and old schooled nutes like ghe, but this is not the topic.
Around the last weeks, I am planning to gradually switch to this:
Target NPK: 0-2-3

AN Overdrive: 0-2.5-2 0.5 pt

GHE FlBloom: 0-2.5-2 0.5 pt

AN Bigbud: 0-2.6-7.8 2.6pt

Tot NPK 0-7.6-12.8 (0-1.9-3.2)

Click to expand...

Would love to see pics of your run at week 4 using the FloraTrio. Lots of use only that, along with their CaliMagic.

Also, if you're at 380-400 ppm in the peak of flower, I'm assuming you're in DWC. That's pretty low for how many different t additives you've got.

i’m in coco drain to waste and ppms are very unusually low considering it’s a single monster plant covering 4x4, but runoff seems to get higher than the imput when I go over 410 for now. Next week i’m gonna try to push 450, but she seems to uptake everything really fast and she’s healthy

There she is. I have better pics and videos that show the full plant, i post them in a grow journal i did on the forum.
This is the most recent pic I have that show bud development around day 26

Well, just cause its healthy, doesn't mean it's not lacking potential. You may or may not be robbing yourself some major weight by using so little nutes

Hi everyone, I am really hoping to get some answers cause right now i’m at the peak of flower with my plant and I wanted to try something different than the usual 13/14.
Thanks a lot

I made tons of researching in the world of agricolture and biology and here’s what i’ve found, comparing to my personal experience with a bit of logic.

Let’s suppose that a plant hasn’t got any limiting environmental factor or nutrient, including perfect balance of ec/ph/vpd and secondary macros like Ca, S and Mg and trace elements.
I’d like to separate the nitrogen level and the p/k level.

VEG
Nitrogen will always be adapted to the plant needs, as it easy to see if toxic of deficient.
As rule of thumb a perfect level would be K being 1.5 times N during veg. (Like Npk 4-2-6)

Phosphorus is more needed during early rooting, but overall it’s a little quantity that is needed and the levels of K should be about 3 times the levels of P during all cicle of veg.
P is super important as plant also make ATP with it

K should be around 2.5-3 times P and 1.5 times nitrogen.

Examples of ideal npk ratios:
Early veg and rooting: 4-3-6
Veg: 4-2-6
Transition: 4-3-6 then 4-3-5 then 4-4-4 in the first two/three weeks of bloom

BLOOM
Nitrogen should be kept same as veg until week 3-4, then should be slowly reduced and almost cut off around 1-2 weeks before flushing.
Phosphorus level should be elevated in early bloom, weeks 2-4, as the plant’s demand will be higher than K and most likely even than N.

Then in mid bloom, week 5 and 6, the level of P should be lowered and be even with the level of K.

In Late bloom, researches in lab horticulture have shown that the plant’s demand of potassium is higher than anything else.
So a rate of 1-2-3 or even 1-2-4 would be perfect, slowly reducing the nitrogen to get around 0-2-3 in the last week or right before flushing

Examples of ideal npk ratios in flower:
Early bloom: 2-3-2
Mid bloom: 2-3-3 to 1-3-4
Late bloom: 1-2-3 to 0-2-3 or 0-4-7 in the very last days of feeding

Does your experience prove something i missed? I’m obviously talking as a rule of thumb, and food should be adapted to the single plant necessity if she shows it

giantcola said:

I am planning to give her progressively less nitrogen and phosphorus to get around
0-2-3 in the last 2 weeks before flush

Click to expand...

N is by far the most important nutrient for cannabis. why starve it at the end?

i won't even bring up the flush/non flush debate.

N actually grows leaves and cellulose, being the structure of the plant and of the bud. Around week 4-5 the plant completely stops growing leaves and produces buds, the amount N is needed just to keep the leaves green and is progressively less.
I am sure that if you over do it with nitrogen during bloom you end up with a leafy plant and less weight

Also I would suppose that all the 17 essential elements are almost equally important for the plant’s correct nutrition, as they interact with each other’s in cell’s reactions and a plant uses all of them to survive and reproduce.
I’m talking about the proportion of nutrient used by the plant, not about the importance of every single element or we should dig much deeper into the world of chemistry

giantcola said:

I am sure that if you over do it with nitrogen during bloom you end up with a leafy plant and less weight

Click to expand...

if you get rid of it completely, you'll get even less weight. but i agree with you, you do need to taper N down but not to 0

are you taking into consideration Ca and Mg or just NPK?

and are these ratios bottle numbers or actual elemental levels?

for Ca:Mg ratios, i've read a few different rules:

some say 2:1 ratio. other places i've read as high as 4:1 or even 6:1

and i'm not a coco grower so i'm giving out more of my thoughts on pure hydro (DWC)

I was considering only npk.
i have pretty much always used around 3-1 ratio for Ca-Mg, but all the dosage is upped through transition and early bloom, and then in mid bloom I get around 5-4 ratio(but less ppms then early bloom). Late bloom approximately i’d say 1-1 but very little dosage, as plant uptakes more mag then calcium when producing oils and resin instead of bulking up.
Also in coco the medium gets deprived of a lot of calcium so i’d say in dwc i’d use 20 to 40% less as well as the iron

You can really play around with these values and find the most appropriate for the plant.

@giantcola
check this thread out. especially the .pdf a few posts down.

The chart at the beginning is amazing, lots of info. Thank you

giantcola said:

The chart at the beginning is amazing, lots of info. Thank you

Click to expand...

no problem. i've been focusing on nute ratios for the last few months at least. my entire system is dialed in and i want to see if i can find the "best" ration kinda like you.

i'm going to try Jack's Tap formula next run. 15-5-20 and then switch to Lucas for last few weeks mainly to drop the N

So the chart is saying about 7-1-7 for veg, i’ll slightly modify some of the values.
Lucas formula is 1 pt micro and 2 pt bloom right? wouldn’t this give u npk 5-10-9? Is not pretty much in line with the low phosphorus amount.. i’ve been running this formula a few times and it grows for shure, but i need more experimentation to find out how well compared to the “teoric” line provided by agricoltural texts

giantcola said:

Lucas formula is 1 pt micro and 2 pt bloom right? wouldn’t this give u npk 5-10-9?

Click to expand...

i've never actually figured out the bottle npk ratio of Lucas. the elemental is 100-100-200 in ppm