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Parts Per Million for Dummies (US) using TSP/Gallon Teaspoon

I Care

Well-known member
If you have a blend that you wish to calculate your Macro and Micronutrient PPM using teaspoons, the conversion is described in this post.

My desire for this thread is that the firstpage contains a reply about the other ratios that affect the raw calculations I have done here. The multiplications necessary to determine the actual available nutrients for those that are not reflected by raw numbers provided by the manufacturer.

I like everybody here, but I want this first page to be the true wealth of converting any food, for anybody who uses any product anywhere in the world as water soluble nutrients. After the boring stuff is out of the way, the next pages would be great for fun and laughs.

An elemental nutrient at 10% added at 1tsp/Gal comes out to 129ppm per gallon.

The calculations for teaspoons are as follows.
(X): represents the elemental nutrient

X = 10.0 Then 1.0 x 129 = 129ppm per Gallon

Now let’s move to an example of a micro nutrient represented by Y
Y = 0.05 Then 0 .005 x 129 = 6.45ppm per Gallon

Now here is an example of a water soluble nutrient thy can be bought at Home Depot.
NPK 12 - 5 - 7 Vigoro All Season All Purpose on hardware store shelves in the US.

N = 12 1.2 x 129 = 154.8 ppm / N
P = 5 .5 x 129 = 64.5 ppm / P
K = 7 .7 x 129 = 38.7

You will continue with the same reduction

The elemental analasys time .1 multiplied by 129 equals the ppm per gallon.


Here is an example of some micros
Ca = 1 .1 x 129 = 12.9 ppm / Ca
S = .4 .04 x 129 = 5.1 ppm / S
Mg= .2 .02 x 129 = 2.58 ppm/ Mg
Zn= .01 .001x129= .129 ppm/ Zn




Edit — improved EQUATION for rough calculations
Multiply guaranteed analysis directly to 12.9 It makes more sense than moving the decimal place in the g/a % N10 x 12.9 is 129ppm/N
I missed this thinking I was a genius lol



Someone please reply with the clarification for further reduction of these numbers based on available P and K and whatever else. I know there is more to this, determining the actual PPMs that is available from water soluble nutrient percentages listed on the packaging.

Thanks, hope we can create something beneficial.

Props to David O’Connor, the guy on the Scottish throne, for sharing this informantion
 

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Creeperpark

Well-known member
Mentor
Veteran
If you have a blend that you wish to calculate your Macro and Micronutrient PPM using teaspoons, the conversion is described in this post.

My desire for this thread is that the firstpage contains a reply about the other ratios that affect the raw calculations I have done here. The multiplications necessary to determine the actual available nutrients for those that are not reflected by raw numbers provided by the manufacturer.

I like everybody here, but I want this first page to be the true wealth of converting any food, for anybody who uses any product anywhere in the world as water soluble nutrients. After the boring stuff is out of the way, the next pages would be great for fun and laughs.

An elemental nutrient at 10% added at 1tsp/Gal comes out to 129ppm per gallon.

The calculations for teaspoons are as follows.
(X): represents the elemental nutrient

X = 10.0 Then 1.0 x 129 = 129ppm per Gallon

Now let’s move to an example of a micro nutrient represented by Y
Y = 0.05 Then 0 .005 x 129 = 6.45ppm per Gallon

Now here is an example of a water soluble nutrient thy can be bought at Home Depot.
NPK 12 - 5 - 7 Vigoro All Season All Purpose on hardware store shelves in the US.

N = 12 1.2 x 129 = 154.8 ppm / N
P = 5 .5 x 129 = 64.5 ppm / P
K = 7 .7 x 129 = 38.7

You will continue with the same reduction

The elemental analasys time .1 multiplied by 129 equals the ppm per gallon.


Here is an example of some micros
Ca = 1 .1 x 129 = 12.9 ppm / Ca
S = .4 .04 x 129 = 5.1 ppm / S
Mg= .2 .02 x 129 = 2.58 ppm/ Mg
Zn= .01 .001x129= .129 ppm/ Zn


Someone please reply with the clarification for further reduction of these numbers based on available P and K and whatever else. I know there is more to this, determining the actual PPMs that is available from water soluble nutrient percentages listed on the packaging.

Thanks, hope we can create something beneficial.

Props to David O’Connor, the guy on the Scottish throne, for sharing this informantion
Thanks for adding your input on nutrients friend. I just use a TDS meter to calculate my parts per million. When using a complete fertilizer the manufacturing scientists have already mixed the ratios for the perfect ppm blend.
 

I Care

Well-known member
Another basic calculation of todays watering
2tsp 2-4-4 General Organics BioThrive Bloom
1tsp 1-0-5 grandmas molasses

2 4 4
2 4 4
1 0 5
5 8 13

.5 x129= 64.5ppm/N
.8 x129= 102.3ppm/P
1.3x129= 167.7ppm/K

.2 x 129 = 25.8ppm/S
.1 x 129 = 12.9ppm/Mg
 

Ca++

Well-known member
1g of 10% strength, in 10L, is 10ppm.
1g of 2.9% strength in 10L, is 2.9ppm
1g of 35% in 10L, is 35ppm

A liter is a 10th of 10L, so we get a result 10x stronger
1g of 10% in 1L is 100ppm
1g of 2.9% in 1L is 29ppm
1g of 35% in 1L is 350ppm

Often we are using fluids, and don't want to weigh them. 1g of water is 1ml. So we can almost say it's the same. With 1ml of 10% in 10L giving us 10ppm, just as 1g did. However, most feed bottles actually give the weight and volume. You often see 1L weighing 1050g which means a 5% error using fluid volume for ppm calcs, instead of using actual weight.

It's metric, and in metric, it's mental arithmetic. No calculator needed. If you start getting the calc out to tap in how many spoons you used, it's a lot of thought, to get a result as accurate as loading a teaspoon.

It's just there for you, if you work in metric. I'm not sure why anyone would make it a math challenge. Just to keep their gallon alive.
 

I Care

Well-known member
Now a ML dropper that would be great if you don’t like getting your hands covered in smelly organics. The plastic blow molded ones since they’re the most consistent. Don’t know how much quality control is done on printed droppers, or the shot glass in my case.

As for gallons, those Arizona tea jugs worked awesome. But I’m no longer fan consuming all of that corn syrup with my lack of moderation. Have a HD jug in a day or two at most but also all the sickys or all that corn. Just a rinsed water jug is really easy for me this round.

With this adding a decimal and counting each added nutrient as 1tsp instead of breaking it down into each individual mL has been really helpful in the process of determining rough accurate nutrient ppm levels.

The tsp has become as easy as moving the decimal point left and multiplying by 129. Whether I do 7tsp of different food or 2tsp, I add it all up and treat those added numbers as if it’s one tsp.

It’s the only way I could find to work smarter without the need for more capital funding. Probe should be in if I ever decide to go to the mailbox, but this really is working for me and my recycling.

This thread is “for dummies” after all.

What is the further reduction? like .42 for available P and .8 for available K? I read it somewhere and wasn’t high at the time, info didn’t totally stick.
 

Ca++

Well-known member
Are you talking oxide to elemental?
I see them move a bit, but use 0.43 and 0.83 myself. It's near enough the same though.
The post-it note has fell off my monitor, or I would list a few more.
 

I Care

Well-known member
Edit: because I cannot edit in a quote
this info from Ca++ “I see them move a bit, but I use 0.43 and 0.83..”



Irie, that’s it there. When trying to keep water from becoming too hard, I wonder if I should be doing what I’m doing or should I be doing it with the oxide to elemental conversion to stay below the threshold. Or which one is the probe going to read, the oxide or elemental?
 
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Ca++

Well-known member
When we talk PPM, it's the elemental value. The part the plant is interested in.

Be careful checking your work with a ppm meter. These meters are conductivity meters, masquerading as something they are not. Money can't buy a ppm meter.

Say you have some 10% Ca solution, and you stick a ml in a L to get 100ppm. We are ignoring 90% of what we just put in. Will the meter see this? Well yes, but how much it see's, is dependent on how conductive the stuff is. Stuff that's not listed, if it's not plant food. Lets say it measures nothing, to keep things simple. Then we just have the elemental portions to measure. Another problem exists, that not all elements have the same conductivity. 100ppm of one could measure as 70ppm, while 100ppm of another could measure 130ppm. In reality, non will measure the same, as they have different conductivity. The ppm meter can't see what element you are measuring to account for the individual conductivity of that element. What the ppm meter does, is compare to a calibration solution, which should be as salty as your complete feed, ideally. This is where it really falls apart, and 50% inaccuracies are seen between results using these standards. With some calibrations made against sodium chloride, and others against more realistic salt solutions. This is where we see the common x500 or x700 multipliers being used by meters from different regions. Though there are others.
In simple terms, the EC is what we measure, and PPM is a big fat liar. Don't trust it to check your work.

I think we got ppm meters from the aquatics shops. Long before we could easily get an EC meter, without offering up a kidney. They just kind of stuck with us, like the gallon. It's not research level measurement. And while some might just scream osmocote, every time they hear a loud noise, it's actually nice to read them research papers, while speaking the same language. So ppm is known when you weigh in the elemental quantities yourself. Tank salt concentrations are seen with a conductivity measurement. Then the papers are much easier to read. That is doing it properly, you could say.
 

I Care

Well-known member
Oh nuggets.

Add everything together I got about 950.

501
501
244
244
244
105
105
105

21-12-29

21 = 2.1 x 129 = 270.9ppm/N
12 = 1.2x 129 = 154.8ppm/P
29 = 2.9x 129 = 372.4ppm/K

It’s the same thing for me afterward looking at macros
One nutrient contains 1% Sulfur and three parts of that nutrient is listed above.

So I do the micros like this
S (sulfur 3pts 1%)
1 1 1 = 3 = .3 x 129 = 38.7ppm/S

Ca (Calcium 2pts 5%)
5 5 = 10 = 1.0 x129 = 129ppm/Ca

Mg
.5 .5 .5 = 1.5 = .15x129=19.35ppm/Mg

Once again
Your percentage % x (0.1) x 129 = ppm

My trick to this, do not concern yourself with 8 teaspoons, concern yourself with those teaspoons as if they are one.
 
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Ca++

Well-known member
I don't really follow that, but you probably don't have 244 you have 223 if you want to talk ppm. Though ppm is getting pretty exacting, so you would look what the numbers really are, rather than rounding them off, as the bottle does. For instance, that 2N could be 1.5N rounded appropriately. Making your results 25% off. If they don't give more exact figures on the bottle, then they are talking minimums. Which makes any value they give a bit worthless. Some feeds just claim to contain tiny tiny amounts, because they have to admit to something. Others tell you what you want to hear. Labeling is very controlled, with pages and pages of legal guidelines, that amount to nothing useful.

If you wanted to do ppm in metric, like it is, I could look over your figures. I would need weights and volumes though, to do it properly.
 

I Care

Well-known member
Those are NPKs, I think you know that.
So going with that .43 and. 83 you mentioned earlier you’re saying to go with the 223?

I think I’m getting this as right as I can get it, minus all the exacting variables. I should have shared the video that gives the formula

 

Ca++

Well-known member
Those are NPKs, I think you know that.
I started off thinking as you. That a bottle saying it has 4% P, has 4% P. It's a reasonable expectation, and published often. However, it's not true. They list the P as a compound. An oxide. Even if it's not.
We must do math to convert what we are told, to the truth. In the UK, the truth is often stated in brackets, beside the conventional compound measurement. In Ireland, they just tell it how it is. That 4% isn't even 2%, if it were indeed 4%. Yes, the 4% is in fact a lie itself. It's a guaranty of what you will find. Which outside of the UK isn't a guaranty you will find that. It's a guaranty you will find at least that.
Essentially, you can't work out the PPM's from this label. It doesn't tell you what is in the bottle, or a figure you can correct with math. It's just numbers to keep everyone happy. Everyone that has no need to know, that it.
 

I Care

Well-known member
Thanks, that really kinda explains it, I do love the UK will be going a new route when I get a chance to start a new round. By then, that meter you put me on to, will be working with batteries. Depending on what I haul out of the tent next month, I may try to get someone to buy me another nutrient line, I can’t help but lean to Canna. Definitely going to plant mother GMO C2 with osmocote just to save myself any aggravation and learn how to use a meter on the next round.
 

I Care

Well-known member
Well, GMO but it did sift well.
Going to get some batteries to celebrate the holiday. Also going to buy a couple gallons of distilled water to play with.

Then I can check out that meter @Ca++ , it says it’s calibrated.
Do you have any simple recommendations, caring for a meter?

These things may need some potash.
 

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Ca++

Well-known member
This is a flash from the past. A lot of numbers I don't remember in any detail. I got your link to work though. I don't know the meter, though was close to buying one recently. Factory calibration seems interesting, but I would still get some fluids to test it. It does read that both EC and pH use 3 point calibration. The pH stuff is a sachet of dust that makes up a bottle of calibration fluid, using the distilled you talk of. While EC is usually as costly as the meter, but can be made with table salt. If you merely wish to check it's close. As table salt isn't as consistent as you might like. It makes me happy enough though.

IIRC it's 0.25g in 250ml to make some sort of useful round number. If you can't weigh 0.25g then weigh something you can, then get your credit card and mirror.
 

I Care

Well-known member
Thanks. I was at the store twice today. Ended up forgetting the distilled twice so… this is the spring water bottle I had here at home. Seems legit.
 

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Ca++

Well-known member
It's nice to see people buying straight from China now, instead of paying the middleman. It's so cheap it can be unbelievable. It's really just how much people have been making in the middle, that's unbelievable though. It makes buying batteries for them painful, but batteries from China are nearly all by boat now. So most things are coming without.
I see you really splashed the cash, getting the back lit one. It must of cost at least a dollar more. I just picked up the typical yellow pH meter, and I'm kicking myself for being so cheap tbh. I sooooo want to stir my jug/bucket/tank with it. But it will die if I get it wet. A meter for water, that you can't get wet. You couldn't make it up.

Do you have a tap water report? Perhaps your tap could also check the calibration is close.
 

I Care

Well-known member
When you showed me that thing and it was free to ship it was just a no brained. The Amazon wants 20 for the same meter with batteries. I think with the Energizer batteries I’m looking at 12 total. I really appreciate it.

I honestly think it may be a much better PPM/TDS meter than a PH meter.
Only reason I’m not giving it total credit on PH is because what I saw today scared me.

Testing the meter. I tested a jug of store bought spring water and it came up 7.25PH and 327PPM if I correctly recall. Then with the well water it came up at 7.10PH and 51PPM, that should nearly be distilled water in the ground after all the snow melt.

The thing that scared me is a below 5.0PH reading today as it slowly dropped from 5.50 to 4.95 after watering with some 6.1 Kelp food, which is very likely mostly some kind of acid preservative after doing nothing but dropping PH 7.1-6.1 with 5ml. That in itself is causing meter PH questionability. Possibly issue with factory calibration solution. Will calibrate myself at some point, using the provided packs of PH powder like you said Ca.

After filling large pots with home blended soil, I did get water running off at 6.1 with the water from the well. So if the meter is correct… I should be between 5.5-5.7 soil PH.

BUT! I’m going to speculate toward the idea that calibration is off in a way, causing it to swing a little further than the actual number on the acidic side.
 

Ca++

Well-known member
The slow drop is often a sign of older used sensors. It might be worth storing in a kci solution for a bit.

My new meter said to hydrate it with distilled water. I very quickly wet it, then stood in a 7. Other meters have died in distilled water. I'm not sure exactly, but many probes have a reference electrode, which sits in a gel I think. Meters are often first hydrated with KCL or put right with KCL regularly. These meters don't like pure water measurements. Pure water is a great solvent, to such things.
I don't know what you have, but how it woke could be more critical then we realise.

A quick search of KCL storage pH, tells me it's 4.01 ffs lol
 
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