• Home
  • Forums
  • Medical Cannabis Cultivation
  • Nutrients and Fertilizers
  • Need help with calculating correct NPK from nutrients

Need help with calculating correct NPK from nutrients

  • Thread starter Thread starter Dance_Instructor
  • Start date Start date Apr 6, 2023
  • Tagged users Tagged users None

Need help with calculating correct NPK from nutrients

Dance_Instructor Apr 6, 2023 6 Replies 4,689 Views
Page 1 of 1 · Replies 1–7 of 7
1
D

Dance_Instructor

Posts
37
Reactions
33
Joined
Feb 12, 2023
Points
18
Apr 6, 2023
#1
Hey,

Im growing in soil, I bought it from the local grow shop.

I have Advanced Nutrients Jungle Juice Base nutrients and also additional stuff from them: Big Bud, B52, Overdrive, Voodoo Juice.

This is the feeding chart I found:



Here there are 2 options:
#1: Use the standard application rates
#2: Use 2nd simple feeding chart.

Also, I saw this NPK ratio guide:



I see the NPK ratios change from time to time, but the feeding chart has the same values all the time.

My plants are now in the transition phase from veg to flower, turned to 12/12

These are the product NPK ratios in 1 liter:
GROW - 20:10:60
MICRO - 50:0:10
BLOOM - 0:50:40
B52 - 20:10:40
Big Bud 0:10:30
Overdrive 10:50:40
Voodoo Juice 0:0:0

So I calculated the NPK with my products and have this result:
Per 1L water:
GROW - 0.5ml
MICRO - 1.2ml -
BLOOM - 1.2ml
Voodoo - 2ml
=
10-5-30
60-0-12
0-60-48
0-0-0
=
70-65-90

So the NPK rato here is 7-6.5-9.0 which is close to 7:7:7

Compared to the "Simple Chart" feeding:
Per 1L water:
GROW - 4
MICRO - 4
BLOOM - 4
Voodoo - 2
=
80-40-240
200-0-40
0-200-160
0-0-0
=
280:240:440
which makes NPK 28:24:44?

I think I'm missing something in my calculation and I couldn't find a proper guide about this anywhere. Any help will be appreciated.
 
Reactions: GNick55
Quote Reply
D

Dance_Instructor

Posts
37
Reactions
33
Joined
Feb 12, 2023
Points
18
Apr 7, 2023
#2
Anyone?
 
Reactions: GNick55
Quote Reply

TomH

Posts
384
Reactions
1,056
Joined
Sep 23, 2021
Points
143
Apr 7, 2023
#3
Man, I was told there would be no math here!

That looks really complex! Something like Flora Nova, one bottle during veg, a different bottle during bloom and viola!
 
Reactions: GNick55
Quote Reply

GNick55

Staff
Supporter
Posts
15,456
Reactions
49,539
Joined
Jan 11, 2020
Points
438
Apr 7, 2023
#4
make your numbers follow something like this..
 
Reactions: simonkay
Quote Reply

H.o.l_407

Posts
8
Reactions
4
Joined
Jan 11, 2021
Points
3
Jul 1, 2023
#5
I just started using it just because of those same reasons.
 
Quote Reply

simonkay

Posts
310
Reactions
374
Joined
Feb 11, 2023
Points
63
Dec 6, 2023
#6
@Dance_Instructor I've been led to believe via Harley Smith that a ratio of 1:1.2 for nitrogen: potassium is better for veg & 1:1.5 for flower and phosphorus should be no more than 80ppms max but bad practices and leeching have made us believe we need much more phosphorus. I've been bottom watering (which reduces phosphorus leeching) and still tweaking my PPMs (using GH flora nova) and this round I'm gonna give more K closer to the 1:1.5 ratio in flower that Harley recommends. I got a photo of his recommended max PPMs but Im still searching for more charts to follow along as different strains will have a wide range of ppm tolerance but it would help us all if we could stick to some sort of ratio for all of them.
 

Attachments

  • IMG_20231006_121702.jpg
    111.8 KB · Views: 2
Quote Reply
S

strawberrydreams

Posts
21
Reactions
10
Joined
Dec 2, 2023
Points
3
Dec 12, 2023
#7
Did you change the P&K values? Most fertilizers list Phosporus as P205 which needs to be converted to elemental P, and Potassium is usually on the bag as K20 which also needs to be converted to elemental K. You need to do this for every ingredient in your recipe before you can add up the NPK% of each and then get a % out of the total volume of fertilizer.

So the original 70-65-90 is actually :
65*0.436 & 90*0.8301
NPK: 70-28.34-74.7

https://www.pubs.ext.vt.edu/content/dam/pubs_ext_vt_edu/spes/spes-201/SPES-201.pdf
 
Last edited: Dec 12, 2023
Reactions: simonkay and N1ghtL1ght
Quote Reply
Page 1 of 1 · Replies 1–7 of 7
1

Thread info

Replies 6
Views 4,689
Started Apr 6, 2023
Latest post Dec 12, 2023
Starter Dance_Instructor
Forum Nutrients and Fertilizers

Latest posts

  • Weak RSO? Error in process or something else?
    • Latest: logic
    • 47 minutes ago
    Concentrates & Processing
  • T
    My 2025 dry ice kief process
    • Latest: TheIslandIsGreen
    • Today at 2:55 AM
    Cannabis Harvesting & Curing
  • AKBB Hawaiian Cat Piss & More
    • Latest: Slutbutt
    • Today at 12:23 AM
    General Indoor Growing
  • White truffle Flower indoors growing green
    • Latest: compostmike
    • Today at 12:09 AM
    Grow Diaries
  • Blazing heat, smoke-filled skies, illegal! What could possibly go wrong?
    • Latest: Oldchucky
    • Today at 12:08 AM
    General Outdoor Growing
  • Home
  • Forums
  • Medical Cannabis Cultivation
  • Nutrients and Fertilizers
  • Need help with calculating correct NPK from nutrients
  • Contact us
  • Terms and rules
  • Privacy policy
  • Help
  • Home
Community platform by XenForo® © 2010-2026 XenForo Ltd.
Menu
Log in

Sign up

  • Home
  • News
  • Classifieds
  • Forums
    • What's new Featured content New posts New Articles New articles New products Latest activity
  • Social
  • Strains
  • Live
  • Learn
  • Brands
X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?

X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?