Renfro
Well-Known Member
Knee deep in pounds. Epic
Understanding and Calculating Nutrient PPM
- Thread starter Renfro
- Start date
TreeFiddy350
Well-Known Member
My stomach just turned thinking of the trim days. Blah
Trout2012
Well-Known Member
Ok question for the PPM master!! I've just started using a PPM meter. Never touched one until now! My question is two of my plants are almost done!! I started adding just ph water to them to get my PPM down they were pretty high leaves were being affected. After adding about half regular water within a few days it had climbed back up in 2 plants reservoirs and went down in the other one!! How is this possible and why?
Trout2012
Well-Known Member
Trout2012
Well-Known Member
This is freaking awesome Thanks Again!!!!
@Renfro
Man, this is so well timed. I just started looking for these online nutrient profile calculators the other day (I've used'em once or twice, cannastats) and I found a couple, but what I really wanted was a program/application of my own to use, and be able to compare profiles of different items/products side by side, etc. So I started looking for that greengenes video where he shows his profiles. I started to think it might be something people are making themselves, like a spreadsheet in excell, where they just input all the calculations and stuff.
So I looked for one's to download. I didn't find any, but I found this thread. I bookmarked it, read the first post (which was great) and figured I'd at least get the understanding down more clearly and be able to (painstakingly) create my own sheet for it. But I'd have to learn excell (I'm a noob at it) and improve my understanding of the calculations etc. I kept searching the net with no results.
Here I am, with excell open, and I have the left column of "elements" input so far. I decide to scroll your thread before I go any further and I'm delighted to see that you have gone above and beyond.
Thank you so much for taking the time to do this, Renfro.
This should be a sticky post; people should know about this. I'll go check it out now, see how it works.
Thanks again!
Man, I'm super happy about this. Lol.
And it's not even an old thread, it's just recent. Perfect timing for me right now.
Thanks Renfro.
Renfro
Well-Known Member
Share it all you like, thats what it's for. Just make sure it works first lol
Cool.
1. Ok, the results liters tabs says "input *gallon* capacity in the box"... Nitpick, unless I missed something.
2. Does the box table under "gallons" or "liters" says "units" because it might be mL OR grams?
3. The "G/Gal" in Adds tab might be written "g/Gal" instead... Nitpick
4. I'm getting conflicting results when comparing with greenleafs own megacrop elemental nutrient calculator. Some elements are not even close, some are off by..reasonable amounts(?), like different rounded than they used maybe? But for example, "Si" looks like you might have a decimal in the wrong spot, or maybe did you forget to separate the element from the molecule in the calculation maybe. Actually it's too far off I think, unless I did something wrong.
I'm testing by putting "1" in the megacrop Adds, and checking the profile in Results. For example, 1g/1L is showing 84.1ppm in the spread sheet (which is clearly insane), MegaCrop calculator shows 0.7800ppm. So unless it's a rounding difference compounded with a "order of magnitude" error, I duno what it is.
Zinc in the sheet says 1.1000, MegaCrop says 0.5900.
5. I don't understand the gallons/liters box. In the Adds tab when I enter "6" in megacrop box, the results tab(s) give me the elemental ppm, but the boxes just have 55 Gal and 200 L in their boxes. So the table under that is telling me what amount to put into that volume of water to at the given rate input in the "adds" for that product?
Thanks.
1. Ok, the results liters tabs says "input *gallon* capacity in the box"... Nitpick, unless I missed something.
2. Does the box table under "gallons" or "liters" says "units" because it might be mL OR grams?
3. The "G/Gal" in Adds tab might be written "g/Gal" instead... Nitpick
4. I'm getting conflicting results when comparing with greenleafs own megacrop elemental nutrient calculator. Some elements are not even close, some are off by..reasonable amounts(?), like different rounded than they used maybe? But for example, "Si" looks like you might have a decimal in the wrong spot, or maybe did you forget to separate the element from the molecule in the calculation maybe. Actually it's too far off I think, unless I did something wrong.
I'm testing by putting "1" in the megacrop Adds, and checking the profile in Results. For example, 1g/1L is showing 84.1ppm in the spread sheet (which is clearly insane), MegaCrop calculator shows 0.7800ppm. So unless it's a rounding difference compounded with a "order of magnitude" error, I duno what it is.
Zinc in the sheet says 1.1000, MegaCrop says 0.5900.
5. I don't understand the gallons/liters box. In the Adds tab when I enter "6" in megacrop box, the results tab(s) give me the elemental ppm, but the boxes just have 55 Gal and 200 L in their boxes. So the table under that is telling me what amount to put into that volume of water to at the given rate input in the "adds" for that product?
Thanks.
Renfro
Well-Known Member
1 - Fixed Thanks!
2 - You are correct, because it could be either.
3 - Fixed, just so you know thats changed in the products tab and reflected elsewhere. I could make that work with the table you mentioned in #2 but I had a reason not to and I can't remember it lol.
4 - I'll have to look into that. I just entered the label percentages and may have gotten something wrong? Megacrop.. I'll check it out. Can you point me to the megacrop calculator please?
5 - Yes that table lets you put the mix tank / reservoir capacity and it will multiply your adds so you know how much to add.
2 - You are correct, because it could be either.
3 - Fixed, just so you know thats changed in the products tab and reflected elsewhere. I could make that work with the table you mentioned in #2 but I had a reason not to and I can't remember it lol.
4 - I'll have to look into that. I just entered the label percentages and may have gotten something wrong? Megacrop.. I'll check it out. Can you point me to the megacrop calculator please?
5 - Yes that table lets you put the mix tank / reservoir capacity and it will multiply your adds so you know how much to add.
Renfro
Well-Known Member
I should note that @ChiefRunningPhist has pointed out an error in my post.
Calcium nitrate percentages were incorrect. I had obtained those from a write up I found on google and I failed to confirm their accuracy.
Here is a link to the reference I used when I made the post.
Here is @ChiefRunningPhist s message with corrections. Thanks so much buddy!
Calcium nitrate percentages were incorrect. I had obtained those from a write up I found on google and I failed to confirm their accuracy.
Here is a link to the reference I used when I made the post.
Here is @ChiefRunningPhist s message with corrections. Thanks so much buddy!
What's good, figured I'd hit you up here instead of on the public thread.
How you getting 19% Ca? Or any of your % numbers?
By weight:
Ca(NO3)2 = 164g/mol
Ca - 40g/mol
N - 14g/mol
O - 16g/mol
(40g/mol) / (164g/mol)
=
24.39% of Ca(NO3)2 is Ca by weight
By mole:
1 mole of Ca(NO3)2 is created from...
1mol of Ca
+
2mol of N
+
6mol of O
=
9 parts
Ca is only 1 part of the total 9 parts, so Ca = 1/9 of the total molar composition, or 11.11% by mole.
Adding to water:
Molar mass of H2O = 18.015g/mol
H - 1.008g/mol
O - 15.999g/mol
(1000g/1L) × (1mol/18.015g)
=
55.5mols of H2O/Liter of H2O
1,000,000mols ÷ 55.5mols/L
=
18,018.02L of H2O needed for 1,000,000 moles of H20
[0.5g Ca(NO3)2] ÷ [164g/mol Ca(NO3)2]
=
0.0030487mols of Ca(NO3)2
It takes 18,018.02L to make up 1,000,000 moles of H2O, or make 1 million parts. So we'd multiply the "per litre" addition of salts by 18,018.02 to achieve a .. "X" parts of salt, per million parts of water.
(0.0030487mols) × (18,018.02)
=
[54.93mols Ca(NO3)2]/[1000000mols H20]
=
54.9PPM
There's only 1 part Ca per every Ca(NO3)2 molecule, while there's actually 2 parts N per every Ca(NO3)2 molecule. This means that for every Ca(NO3)2, there's 1 part Ca, so the molar PPM of Ca when adding 0.5g of Ca(NO3)2 to 1L of H20 is the exact same as the molar PPM of the entire Ca(NO3)2 amount added to 1L, or as we calculated earlier, 54.9 PPM. This is less than the molar PPM of N because there's 2 parts N in every Ca(NO3)2. So, we'd multiply the molar PPM of Ca(NO3)2 by 2 to achieve the molar PPM of N.
{[54.9mols Ca(NO3)2]/[1000000mols H2O]} ×
(2 parts N per 1 part Ca(NO3)2)
=
(109.86 mols N)/(1000000mols H20)
^^^^That's all molar^^^^
This next stuff is all about "by weight"...
There's 1,000g/1L, so wed need 1,000L to achieve 1,000,000g, or a million parts. So our multiplier is going to be 1,000 this time around.
Molar mass of Ca(NO3)2 = 164g/mol
Molar mass of Ca = 40g/mol
Molar mass of N = 14g/mol
Grams of Ca(NO3)2 added = 0.5g
164 ÷ 0.5
=
0.0030487mol Ca(NO3)2
0.0030487mols × 1mol Ca
=
0.0030487mol Ca
0.0030487mols Ca × 40g/mol
=
0.12195g Ca
0.0030487mols × 2mols N
=
0.0060975mols N
0.0060975mols N × 14g/mol
=
0.0853g of N
Multiply the weights of the elemental parts of the salt by (1000) to achieve the total parts of salt per 1million parts of water.
0.12195g Ca × 1000
=
121.95 PPM of Ca
0.0835g N × 1000
=
83.5 PPM of N
I might be overlooking something, but this is where I'm at..
ChiefRunningPhist
Well-Known Member
It's a great thing to tackle, props on your progress! Very useful and a great tool you are designing!
Renfro
Well-Known Member
So I input the megacrop label values from their website
into the Tools tab (Label Calculator Easy Mode) to get the PPM values for the product tab (hope I didn't fuck it up lol) I updated the product values as some of the numbers were off (the green box shows the PPM values that get pasted to the product tab. I may have found a bad label percentage listing the first time. Let me know how this correction works for you. Thanks so much for your help. Here is the updated version. I left the label values in the tools tab calculator for ya, you can just zero them out.
Here is the results
Renfro
Well-Known Member
I really appreciate everyones input and help getting this right. I am far from perfect, smoke too much weed probably, but I do hope to make this a useful tool for anyone that wants to use it.
Honestly it has gone a lot farther than I expected. lol
4 - Here's their calculator. Two tabs, one is feeding chart, other is elemental. https://greenleafnutrients.com/feeding-calculator/?v=7516fd43adaa#1503551740849-5add0c8a-5261
3 - The "G" in G/Gal on the "Adds" page is fixed by a change made on the products page? Interesting.
You could shoot greenleaf nutrients a very brief email. I know they've change their formula quite recently with changes "minor" enough that there isn't an actual "notice" anywhere and it's not specific what *exactly* that increased, you know, amount wise - and I don't think the label has changed either. It's like a Version 2.5 of their formula. It wouldn't account for most if not all the errors I pointed out though, I don't think. But maybe for a slight difference in the "P" for example.
I'll try to look further through the pages/sheets and stuff. Gotta do a lil work.
I also have no real clue about what "macros" are - so just gotta read the info on that.
Thanks