Trouble calculating ppm for General Hydroponics

S

studboy

Active Member
I'm so frustrated with this that I've strained my mind. I want to calculate the final ppm concentration of nitrogen of my nutrient solution. Can someone please give me the equations for calculating the ppm? Micro is 5% nitrogen (5-0-1). That means if I take 1 ml of micro, I have 5% of a ml of N, or .05 X 1 = .05 ml N. If I take that .05 ml of N and dilute it with 3785 ml of water, I get .05 ml N in 3786 ml of water which is .0000132 or 13.2 ppm . But that's not right! When I usethe same math for all 3 solutions and compare my results to the ppm in the grow charts, I'm way off. My purpose for this is to have a spreadsheet that calculates the final N in ppm for my mixed nutrient solution with all 3 parts and the additives such as liquid seaweed, cal mag, etc. What am I doing wrong? Thanks!
 
futurebanjo

futurebanjo

Well-Known Member
I prefer to use EC as a measurement, as there are a few different ways (2 main ways) of calculating PPM, so it depends on what tool you are using to take the reading.
 
GrnMonStr

GrnMonStr

Well-Known Member
I wanted to see what ChatGPT would say here are the results. Does this help at all?? I have no idea myself since I grow is soil.

To calculate the final parts per million (ppm) concentration of nitrogen in your nutrient solution, you need to know the following:

  1. Concentration of Nitrogen Source: This is typically given in percentage (%) or grams per liter (g/L).
  2. Total Volume of Nutrient Solution: This is the total amount of solution you have mixed or intend to use.
Here’s how you can calculate it:

Step-by-Step Calculation
  1. Convert Nitrogen Source to ppm:
    • If the nitrogen concentration is given in percentage (%):
      Nitrogen concentration in ppm=Nitrogen percentage×10,000\text{Nitrogen concentration in ppm} = \text{Nitrogen percentage} \times 10,000Nitrogen concentration in ppm=Nitrogen percentage×10,000
      For example, if your solution is 2% nitrogen:
      Nitrogen concentration=2×10,000=20,000 ppm\text{Nitrogen concentration} = 2 \times 10,000 = 20,000 \text{ ppm}Nitrogen concentration=2×10,000=20,000 ppm
    • If the nitrogen concentration is given in grams per liter (g/L):
      Nitrogen concentration in ppm=Nitrogen concentration in g/L×1,000\text{Nitrogen concentration in ppm} = \text{Nitrogen concentration in g/L} \times 1,000Nitrogen concentration in ppm=Nitrogen concentration in g/L×1,000
      For example, if your solution has 5 g/L of nitrogen:
      Nitrogen concentration=5×1,000=5,000 ppm\text{Nitrogen concentration} = 5 \times 1,000 = 5,000 \text{ ppm}Nitrogen concentration=5×1,000=5,000 ppm
  2. Calculate Final ppm of Nitrogen:
    • Once you have the ppm concentration of nitrogen from the source, you need to consider the dilution factor if you have mixed this concentrate into a larger volume of water.
      Let's denote:
      • CsourceC_{\text{source}}Csource: Concentration of nitrogen from your nutrient source (in ppm).
      • VtotalV_{\text{total}}Vtotal: Total volume of your nutrient solution (in liters).
    • If you have diluted the nitrogen source to prepare your nutrient solution, the final ppm of nitrogen in the solution can be calculated using the dilution formula:
      Final ppm of Nitrogen=Csource×VsourceVtotal\text{Final ppm of Nitrogen} = \frac{C_{\text{source}} \times V_{\text{source}}}{V_{\text{total}}}Final ppm of Nitrogen=VtotalCsource×Vsource
      where VsourceV_{\text{source}}Vsource is the volume of the nitrogen source (in liters) used to prepare the total solution.
Example
Let's say you have:

  • Nitrogen concentration in your source solution: 20,000 ppm
  • Total volume of your nutrient solution: 100 liters
If you use 10 liters of the source solution to make up the total 100 liters of nutrient solution, then the final ppm concentration of nitrogen would be:

Final ppm of Nitrogen=20,000×10100=2,000 ppm\text{Final ppm of Nitrogen} = \frac{20,000 \times 10}{100} = 2,000 \text{ ppm}Final ppm of Nitrogen=10020,000×10=2,000 ppm
This means your final nutrient solution would have a nitrogen concentration of 2,000 ppm.

Make sure to adjust the calculations based on your specific concentrations and volumes to get the accurate final ppm concentration of nitrogen in your nutrient solution.
 
S

studboy

Active Member
GrnMonStr said:
I wanted to see what ChatGPT would say here are the results. Does this help at all?? I have no idea myself since I grow is soil.

To calculate the final parts per million (ppm) concentration of nitrogen in your nutrient solution, you need to know the following:

  1. Concentration of Nitrogen Source: This is typically given in percentage (%) or grams per liter (g/L).
  2. Total Volume of Nutrient Solution: This is the total amount of solution you have mixed or intend to use.
Here’s how you can calculate it:

Step-by-Step Calculation
  1. Convert Nitrogen Source to ppm:
    • If the nitrogen concentration is given in percentage (%):
      Nitrogen concentration in ppm=Nitrogen percentage×10,000\text{Nitrogen concentration in ppm} = \text{Nitrogen percentage} \times 10,000Nitrogen concentration in ppm=Nitrogen percentage×10,000
      For example, if your solution is 2% nitrogen:
      Nitrogen concentration=2×10,000=20,000 ppm\text{Nitrogen concentration} = 2 \times 10,000 = 20,000 \text{ ppm}Nitrogen concentration=2×10,000=20,000 ppm
    • If the nitrogen concentration is given in grams per liter (g/L):
      Nitrogen concentration in ppm=Nitrogen concentration in g/L×1,000\text{Nitrogen concentration in ppm} = \text{Nitrogen concentration in g/L} \times 1,000Nitrogen concentration in ppm=Nitrogen concentration in g/L×1,000
      For example, if your solution has 5 g/L of nitrogen:
      Nitrogen concentration=5×1,000=5,000 ppm\text{Nitrogen concentration} = 5 \times 1,000 = 5,000 \text{ ppm}Nitrogen concentration=5×1,000=5,000 ppm
  2. Calculate Final ppm of Nitrogen:
    • Once you have the ppm concentration of nitrogen from the source, you need to consider the dilution factor if you have mixed this concentrate into a larger volume of water.
      Let's denote:
      • CsourceC_{\text{source}}Csource: Concentration of nitrogen from your nutrient source (in ppm).
      • VtotalV_{\text{total}}Vtotal: Total volume of your nutrient solution (in liters).
    • If you have diluted the nitrogen source to prepare your nutrient solution, the final ppm of nitrogen in the solution can be calculated using the dilution formula:
      Final ppm of Nitrogen=Csource×VsourceVtotal\text{Final ppm of Nitrogen} = \frac{C_{\text{source}} \times V_{\text{source}}}{V_{\text{total}}}Final ppm of Nitrogen=VtotalCsource×Vsource
      where VsourceV_{\text{source}}Vsource is the volume of the nitrogen source (in liters) used to prepare the total solution.
Example
Let's say you have:

  • Nitrogen concentration in your source solution: 20,000 ppm
  • Total volume of your nutrient solution: 100 liters
If you use 10 liters of the source solution to make up the total 100 liters of nutrient solution, then the final ppm concentration of nitrogen would be:

Final ppm of Nitrogen=20,000×10100=2,000 ppm\text{Final ppm of Nitrogen} = \frac{20,000 \times 10}{100} = 2,000 \text{ ppm}Final ppm of Nitrogen=10020,000×10=2,000 ppm
This means your final nutrient solution would have a nitrogen concentration of 2,000 ppm.

Make sure to adjust the calculations based on your specific concentrations and volumes to get the accurate final ppm concentration of nitrogen in your nutrient solution.
Click to expand...
It is helpful, thank you! It's similar to what I got when I used Gemini but it's also a little different than what GH reports on their chart.
 
C

cage

Well-Known Member
1ml/l of 5% nitrogen solution (micro) would make 50ppm solution.

So you *10000 the 5% solution to make ppm's,
then /1000 to adjust for 1ml 5% nitrogen solution per 1000ml(1liter) of water
 
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