The ratios?

Renfro said:

Also, if you have elemental numbers and wish to convert it to the "standard" N-P-K values used on packaging for comparison sake, you can divide the elemental #'s by the conversion percentages.

So if you have a mix that has these elemental #'s

N =120 mg/l
P = 90 mg/l
K = 200 mg/l

N = 120
P = 90 / 0.436
K = 200 / 0.83

thus:

N = 120
P = 206
K = 241

thus we can round it and factor it down by say 10

N = 12
P = 20.6
K = 24.1

12-20.6-24.1

or by a factor of 100

N-P-K = 1.2-2-2.4

Click to expand...

So if you would recommend a 1-2-3 NPK ratio for flower. I would want to take my final elemental PPM numbers and convert them back to standard NPK numbers?
I downloaded your calc, amazing work BTW. Appears the elemental numbers for Mega Crop 9-6-17 the one part mix are different than what GLN show on their elemental calculator, I'm guessing the spreedsheet numbers may have been for the old formula. I added a new entry for the MC version 2 with their elemental numbers and also an entry for GLN Bud Explosion 0-19-39. This is what I came up with for my nutrient mix.



Total nutrient mix = 2 ml/gal CAliMAGic, 2.75 mg/gal Mega Crop, 0.75 g/gal GLN Bud Explosion, 0.75 g/gal Epsom Salts.

Elemental PPM numbers
N = 78
P = 41
K = 177

N = 78
P = 41 / 0.436
K = 177 / 0.83

N = 78 / 78
P = 94.04 / 78
K = 213.25 / 78

NPK ratio
1 : 1.2 : 2.73

Does this look correct?

twentyeight.threefive said:

So if you would recommend a 1-2-3 NPK ratio for flower. I would want to take my final elemental PPM numbers and convert them back to standard NPK numbers?
I downloaded your calc, amazing work BTW. Appears the elemental numbers for Mega Crop 9-6-17 the one part mix are different than what GLN show on their elemental calculator, I'm guessing the spreedsheet numbers may have been for the old formula. I added a new entry for the MC version 2 with their elemental numbers and also an entry for GLN Bud Explosion 0-19-39. This is what I came up with for my nutrient mix.

View attachment 4774958

Elemental PPM numbers
N = 78
P = 41
K = 177

N = 78
P = 41 / 0.436
K = 177 / 0.83

N = 78 / 78
P = 94.04 / 78
K = 213.25 / 78

NPK ratio
1 : 1.2 : 2.73

Does this look correct?

Click to expand...

I was just about to post this; beat me to it!

I have the 1 part MC thats why I was asking thank you guys for showing the science behind why this product might not be construed as perfect.

Renfro said:

Also, if you have elemental numbers and wish to convert it to the "standard" N-P-K values used on packaging for comparison sake, you can divide the elemental #'s by the conversion percentages.

So if you have a mix that has these elemental #'s

N =120 mg/l
P = 90 mg/l
K = 200 mg/l

N = 120
P = 90 / 0.436
K = 200 / 0.83

thus:

N = 120
P = 206
K = 241

thus we can round it and factor it down by say 10

N = 12
P = 20.6
K = 24.1

12-20.6-24.1

or by a factor of 100

N-P-K = 1.2-2-2.4

Click to expand...

So with this ratio, my NPK would be
N: 156
P: (24/0.436) = 55
K: (111/0.83) = 133

Or: 15.6/5.5/13.3 if reduced by a factor of 10. So basically it has nothing to do with diving the lowest value nutrient (in my case P at 5.5) into the next nutrient to determine the ratio? So it would not be an NPK of 2.84/1/2.42, correct @Renfro ?

BDGrows said:

View attachment 4775217
So with this ratio, my NPK would be
N: 156
P: (24/0.436) = 55
K: (111/0.83) = 133

Or: 15.6/5.5/13.3 if reduced by a factor of 10. So basically it has nothing to do with diving the lowest value nutrient (in my case P at 5.5) into the next nutrient to determine the ratio? So it would not be an NPK of 2.84/1/2.42, correct @Renfro ?

Click to expand...

what is your source of p and k? is it pure P and K?

kovidkough said:

what is your source of p and k? is it pure P and K?

Click to expand...

I could be wrong but if they are mono phosphates or mono potassium then you don't divide by anything you only remove the decimal .
so yours would be 156 / 24 / 111 or 15.6 /2.4 / 11.1 or 1.56 / .24 / 1.11 if the source of PK are pure

I think he divided by .43 because that source of P is only 43% actual P and the other is inert

ren would have to confirm

kovidkough said:

what is your source of p and k? is it pure P and K?

Click to expand...

Its P2O5 & K2O from GLNs Part A 5-12-26,

BDGrows said:

Its P2O5 & K2O from GLNs Part A 5-12-26,

Click to expand...

ok then I think your math checks out

I've learned a ton on this thread , thank you all
I use the 9-6-17 , I remove the calnit balls for flower but have no idea the effect on the N ratio i assume ive lowered it

BDGrows said:

I was wondering if anyone could point me in the right direction or shed some light on the preferred ratios of calcium to phos as well as Fe : Mn. Im giving a go at mixing my own nutes and I just wanna make sure everything is balanced so I don't have a headache down the line... Ie for flower I used @Renfro's calc and came up with this for a 1/3/2 bloom...
View attachment 4774391

Click to expand...

Your FE to Mn is perfect. You want equal. or the Mn a tik higher then FE. This will promote THC production.
If it's flipped, and the FE is higher. You get more CBD production.

I prefer to set my soils Fe and Mn at as close to 100 ppm as I can. Keeping the Mn a bit higher at like 100ppm available FE and 110 or so available Mn.