ppm question

croniccrag

croniccrag

Well-Known Member
Can somebody help me understand all this :joint:
Or am i just being thick .They must be a another place to learning about what solution measurements to use and how?
Or maybe iam getting me self in to deep !! i aint even got got me set up yet got to wait till after christmas for obvous reasons.
Anyways can someone explain this a bit better?
I thought i knew a little bit about fertalizers and ppm but now iam lost i fell like albert einstien trying to work all that out and i think he went man did.nt he? Soo HELP please
Before i go mad:?

Thank's inadvance

To figure out the ppm of your fertilizer (or fertilizer mix), you need to be able to measure grams and liters. Look at the 3 numbers on the side of a fert bag. These are the percent content of the nutrients. For every one gram of said fertilizer in one liter of water, it contributes 10 ppm of the given nutrient per percentage point. A 20-20-20 gives 200 ppm (10 ppm X 20) of each nutrient for each gram in a liter of water.

The formula is this:
grams of fert per liter = A/B
A=your desired ppm
B=10 ppm X the % of nutrient in mix
or
your ppm = C X B
B=10 ppm X the % of nutrient in mix
C= grams of fert per liter

So to make a 200 ppm-100 ppm-200 ppm NPK mix using a 13-0-44 (potassium nitrate), a 12-62-0 (monoamonium phosphate), and a 33-0-0 (ammonium nitrate) you would work backwards from your sole P and K sources (it makes it easiest in this case), and make up the N at the end. I have rounded numbers to the nearest 0.1 g for the following. You would use 0.5 g of potassium nitrate (200 ppm/(10 ppm X 44 K)) and 0.2 g of monoammonium phosphate (100 ppm/(10 ppm X 62 P)) in one liter. This would give you 89 ppm N (10 ppm X 13 N X 0.5 g + 10 ppm X 12 N X 0.2 g), 124 ppm P (10 ppm X 62 P X 0.2), and 220 ppm K (10 ppm X 44 K X 0.5 g). 111 ppm are needed to raise the N to the 200 ppm level, so we can use 0.3 g of the ammonium nitrate (111 ppm/(10 ppm X 33 N)) to bring us up to finish.

The actual mix would yield a 188 ppm N, 124 ppm P, 220 ppm K mixture in one liter of water. To get more precision, you need to mix larger batches or get a better scale (you would need to make a 10 liter batch of the above with a scale that is only accurate to the gram).

If you mix your own fertilizer, you can adjust your N source to meet your pH needs, rather than being dependent on adding acid or base, which is nice.

This works for formulating hydro mixes, as well as for us dirt farmers
 
croniccrag

croniccrag

Well-Known Member
Hi gardenknowm i know about the ppm meter and ph..What i need help with is what fertalizer to use ive read on this site(how to grow marijuana LINK)..That i should use a npk of 20 5 5 when vegetating and then switch to a npk 5 15 15 when flowering WHERE are these fertalizer's of this npk?

And i understand that the ppm for seedling and clones starts at about 150 ppm and then you add more fertalizer like bump it up to 500ppm after ten days.when its ready for budding it wants to be around 1000 ppm.<<<<<BUT surely this will need a fertalizer change from veg to flower?

And i understand that the ph should remain around 5.5.

You, have taught me alot but ive jus got a few links missing not quite wired into yet thanks for your patience and help..
 
mogie

mogie

Well-Known Member
If you have any desire to mix your own fertilizers, it is important that you have at least basic understanding of these terms

Electricity is conducted due to the presence of ions (electrically charged) in a solution. The ions get there by introduction of salts via our ferts!

EC (electric conductivity) is a representation of how much potential a solution has to conduct electricity...SO, by testing the ability of a solution to conduct electricity, we can indirectly determine the amount of salts present....thereby knowing if we have the right concentration of ferts.

E.C. is a measure of salinity by measuring its conductivity. You want an E.C. under 2.0.....anything around 4.0 signifies an extreme excess of salt which calls for immediate leeching. There are devices for measuring...honestly, I haven't bought one because I am pretty comfortable with this....but if you experiment may be worth a look!

Despite my natural aversion for ppm measurement, it would be a good idea when mixing ferts as a beginner. Check your nursery or Home Depot. I've F-ed up a plant or two in my day, always because I THOUGHT I was more accurate with eye measurement than I really was!
CF (Conductivity Factor) basically represents the same information but expressed differently. 1 ms/cm is equal to a CF of 10. I don't use this factor and haven't seen many people use it...but just in case, you now have a conversion!

TDS is a measurement, by weight, of the Total Dissolved Solids in a solution and is measured in PPMs (Parts Per Million). Basically, when you hear someone say they introduce nutrients at a rate of 500 PPMs, it means that they have 500 milligrams of solid dissolved in a Liter of water.

You can figure the PPM of your ferts one of two ways.....you can precisely measure the ferts and water you mix together...or you can make a solution and measure the PPM of IT. The shortcut lies in hand-held meters which measure the EC of a solution and then apply mathematical conversion to the EC figure to arrive at PPMs. Keep in mind, even this is an approximate measurement...but plenty accurate for growers!

Some meters actually display the EC AND the PPM readings. Some only express the EC value and this can be tricky because European and American made meters measure at different rates.
An American device that displays an E.C. of 1.0 has 500PPMs.
A European device that displays an E.C. of 1.0 has 640PPMs.
(I believe Australian manufacturers have a different conversion factor also...but not sure.)

So if your American device only displays E.C., use that old algebra and set the two given equations equal to each other. For example, let's say your E.C. reading is 1.2.

Using the known ratio given just above, we'll cross multiply to solve for x to get the unknown ppms.
1.0/500ppm=1.2/x
x=600
Your solution has 600PPMs. (remember, this would be with the American device...a European device would produce a different result!)

If you want to figure out the PPMs yourself, its pretty easy. Each 1 gram of fertilizer per liter of water gives 10PPMs of each given nutrient per percentage point. Sounds clumsy, wish I could state that better....here's an example.

Use 1 gram of SuperPhosphate 0-20-0 in a liter of DISTILLED water. The solution would have 0ppm of N, 200ppm of P, and 0ppm of K. Also keep in mind that tap water already has dissolved solids...most likely anywhere between 200-400 PPMs. Use distilled water when possible...0 PPMs!!

A guideline for NPK strengths
Now, I have seen different parameters for acceptable PPMs. Here is a decent guideline for the N-P-K standards...play around, but make only gradual changes up! Approximate tolerance range of PPMs per nutrient .... most micronutes are tolerated by plants within the same ranges...but the plant just doesn't need nearly that much!

N 200-400
P 200-600
K 200-600

Approximate tolerance range of TOTAL PPMs in soil/medium
(Obviously the plant can tolerate more as it gets larger and has more root area to uptake nutes and leaf area to transpire water.)

Seedling 500-600
Vegetative 800-1000
Flowering 1000-1500
Flushing 500

PPMs for each growth phase
You may desire more N during veg stages for example. The key is NOT to obsess over the exact numbers. Too many experienced growers give advice in exact parameters to appear 'scientific' or something...but there are too many other factors involved in the actual UPTAKE of these nutrients by roots to claim specificity. These are just general parameters that you can tweak under your own conditions. And again, the plant can tolerate more as it gets larger and has more root area to uptake nutes and leaf area to transpire water...start light, gradually increase with each feeding as your lant can handle it.

Keep in mind, my estimates are given for soil mediums which can tolerate higher levels because the soil components will bond with many elemental ions....a hydro system needs to be more precise....I'm not very familiar with those systems. You've read the dislaimer! Also remember that these parameters are based on the assumption of using DISTILLED water. Tap water will add another 200-400 PPMs, so you would have to adjust accordingly...especially with Cl, Ca, Na, and in rare case, S.

SEEDLING (2-3 weeks...look for 4-5 sets of alternating nodes before moving to veg)

N 150
P 100
K 150
Ca 75
Mg 75
S 25-50
Fe 15
Cl 15
Mn 7
Cu 9
Zn 3
Total: 600ppm

VEGETATIVE/PRE-FLOWER (2-4 weeks)

N 300
P 100
K 200
Ca 100
Mg 100
S 50-75
Fe 25
Cl 25
Mn 10
Cu 15
Zn 5
Total: @1000pm

FLOWER (strain dependent-usually 6-8 weeks)

N 300-400
P 400
K 200
Ca 100-150
Mg 100-150
S 100-150
Fe 25+
Cl 25+
Mn 10
Cu 15
Zn 5
Total: @1300-1500ppm

FLUSH/HARVEST (2 weeks)
N 0
P 75
K 75
Ca 50
Mg 50
S 50
Fe 25
Cl 25
Mn 10
Cu 15
Zn 5
Total: @400ppm

I cannot stress enough that these are estimates...conservative ones due to the fact that chemical ferts allow less room for error. In addition, different strains and conditions will result in different ratios....experiment often and use caution always!
 
N

Nunia720$

New Member
mogie said:
If you have any desire to mix your own fertilizers, it is important that you have at least basic understanding of these terms

Electricity is conducted due to the presence of ions (electrically charged) in a solution. The ions get there by introduction of salts via our ferts!

EC (electric conductivity) is a representation of how much potential a solution has to conduct electricity...SO, by testing the ability of a solution to conduct electricity, we can indirectly determine the amount of salts present....thereby knowing if we have the right concentration of ferts.

E.C. is a measure of salinity by measuring its conductivity. You want an E.C. under 2.0.....anything around 4.0 signifies an extreme excess of salt which calls for immediate leeching. There are devices for measuring...honestly, I haven't bought one because I am pretty comfortable with this....but if you experiment may be worth a look!

Despite my natural aversion for ppm measurement, it would be a good idea when mixing ferts as a beginner. Check your nursery or Home Depot. I've F-ed up a plant or two in my day, always because I THOUGHT I was more accurate with eye measurement than I really was!
CF (Conductivity Factor) basically represents the same information but expressed differently. 1 ms/cm is equal to a CF of 10. I don't use this factor and haven't seen many people use it...but just in case, you now have a conversion!

TDS is a measurement, by weight, of the Total Dissolved Solids in a solution and is measured in PPMs (Parts Per Million). Basically, when you hear someone say they introduce nutrients at a rate of 500 PPMs, it means that they have 500 milligrams of solid dissolved in a Liter of water.

You can figure the PPM of your ferts one of two ways.....you can precisely measure the ferts and water you mix together...or you can make a solution and measure the PPM of IT. The shortcut lies in hand-held meters which measure the EC of a solution and then apply mathematical conversion to the EC figure to arrive at PPMs. Keep in mind, even this is an approximate measurement...but plenty accurate for growers!

Some meters actually display the EC AND the PPM readings. Some only express the EC value and this can be tricky because European and American made meters measure at different rates.
An American device that displays an E.C. of 1.0 has 500PPMs.
A European device that displays an E.C. of 1.0 has 640PPMs.
(I believe Australian manufacturers have a different conversion factor also...but not sure.)

So if your American device only displays E.C., use that old algebra and set the two given equations equal to each other. For example, let's say your E.C. reading is 1.2.

Using the known ratio given just above, we'll cross multiply to solve for x to get the unknown ppms.
1.0/500ppm=1.2/x
x=600
Your solution has 600PPMs. (remember, this would be with the American device...a European device would produce a different result!)

If you want to figure out the PPMs yourself, its pretty easy. Each 1 gram of fertilizer per liter of water gives 10PPMs of each given nutrient per percentage point. Sounds clumsy, wish I could state that better....here's an example.

Use 1 gram of SuperPhosphate 0-20-0 in a liter of DISTILLED water. The solution would have 0ppm of N, 200ppm of P, and 0ppm of K. Also keep in mind that tap water already has dissolved solids...most likely anywhere between 200-400 PPMs. Use distilled water when possible...0 PPMs!!

A guideline for NPK strengths
Now, I have seen different parameters for acceptable PPMs. Here is a decent guideline for the N-P-K standards...play around, but make only gradual changes up! Approximate tolerance range of PPMs per nutrient .... most micronutes are tolerated by plants within the same ranges...but the plant just doesn't need nearly that much!

N 200-400
P 200-600
K 200-600

Approximate tolerance range of TOTAL PPMs in soil/medium
(Obviously the plant can tolerate more as it gets larger and has more root area to uptake nutes and leaf area to transpire water.)

Seedling 500-600
Vegetative 800-1000
Flowering 1000-1500
Flushing 500

PPMs for each growth phase
You may desire more N during veg stages for example. The key is NOT to obsess over the exact numbers. Too many experienced growers give advice in exact parameters to appear 'scientific' or something...but there are too many other factors involved in the actual UPTAKE of these nutrients by roots to claim specificity. These are just general parameters that you can tweak under your own conditions. And again, the plant can tolerate more as it gets larger and has more root area to uptake nutes and leaf area to transpire water...start light, gradually increase with each feeding as your lant can handle it.

Keep in mind, my estimates are given for soil mediums which can tolerate higher levels because the soil components will bond with many elemental ions....a hydro system needs to be more precise....I'm not very familiar with those systems. You've read the dislaimer! Also remember that these parameters are based on the assumption of using DISTILLED water. Tap water will add another 200-400 PPMs, so you would have to adjust accordingly...especially with Cl, Ca, Na, and in rare case, S.

SEEDLING (2-3 weeks...look for 4-5 sets of alternating nodes before moving to veg)

N 150
P 100
K 150
Ca 75
Mg 75
S 25-50
Fe 15
Cl 15
Mn 7
Cu 9
Zn 3
Total: 600ppm

VEGETATIVE/PRE-FLOWER (2-4 weeks)

N 300
P 100
K 200
Ca 100
Mg 100
S 50-75
Fe 25
Cl 25
Mn 10
Cu 15
Zn 5
Total: @1000pm

FLOWER (strain dependent-usually 6-8 weeks)

N 300-400
P 400
K 200
Ca 100-150
Mg 100-150
S 100-150
Fe 25+
Cl 25+
Mn 10
Cu 15
Zn 5
Total: @1300-1500ppm

FLUSH/HARVEST (2 weeks)
N 0
P 75
K 75
Ca 50
Mg 50
S 50
Fe 25
Cl 25
Mn 10
Cu 15
Zn 5
Total: @400ppm

I cannot stress enough that these are estimates...conservative ones due to the fact that chemical ferts allow less room for error. In addition, different strains and conditions will result in different ratios....experiment often and use caution always!
Click to expand...
I must be nuts, replying to a 15 year old thread when I haven't posted on this site since about that amount of time. Anyways, Mogie the fact that his question clearly demonstrated that he (Coin) clearly had/has insanely better understanding of how things really work but you went thru that rant trying to belittle him!! Let alone you answered the question pretty quick like in the book you wrote but had no frickin clue, INSANE!!! That's why we are screwed as a whole......he just wanted the numbers. You know, the part IN THE BEGINNING when you said that 1 gram he was originally asking about=10 ppm per Litre?????? STOP
BREAK

So thanks for answering his and my question man. Numerous google search's and I couldn't find the numbers. Prolly cause you Sheeple havent thought 2 ask that question in the last 16 frickin years!!!♨ I do apologize man but I cant take it at this age. I've spent almost 50 odd years feeling alone out here, dumbing myself down with drugs and alcohol so i can tolerate the majority of people. Last mean comment, I mean its like 80% of the world has down syndrome but you actually don't know it. And that sucks because they are more than tolerable, there actually insanely kind. Okay, said I stop. I know Im kinda crazy. But i promised I was telling the truth about everything all the time from now on. Seriously I am sorry, I do realize no one will probably see this. But I'm hoping someone will. I was on this site years ago. Had a couple DWC grows, I think my screen name was Nunia720.... think Wmii was here. We all bounced because it was 2 much like Nazi Germany. Good growers tho, thanks and I do apologize for my insanity. Check my Journals, I'm about 2 see if they are still here.
 
N

Nunia720$

New Member
And please if by some chance you are on this site still, accept my apology. Or show me how I'm wrong. Not just talk about my grammar or something
 
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