NPK Conversion

[Slowitdown]

Was trying to find out how I can actually do the math on N-P-K myself and found this. I am sure most of you already know how to break it down but for those who don't -

Method for converting an N-P-K value to an actual composition
The factors for converting from P2O5 and K2O values to their respective P and K elemental values are as follows:

• P2O5 consists of 56.4% oxygen and 43.6% elemental phosphorus. The percentage (mass fraction) of elemental phosphorus is 43.6% so elemental P = 0.436 x P2O5

• K2O consists of 17% oxygen and 83% elemental potassium. The percentage (mass fraction) of elemental potassium is 83% so elemental K = 0.83 x K2O

• Nitrogen values represent actual nitrogen content so these numbers do not need to be converted.

Using these conversion factors we can determine that an 18−51−20 fertilizer contains by weight:

• 18% elemental (N)
• 22% elemental (P), and
• 17% elemental (K)

 

[caveman4.20]

My years working at the grow shop companys have told me the NPK on the bottle label is what is readily available from the bottle it's a complete different chemistry once diluted and introduced to rizhosphere this is especially critical in organics fir which much of what's in the bottle isn't available until broken down in the rizhosphere

 

[Slowitdown]

Why is it different diluted though?