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Old 03-21-2010, 09:22 PM
Luches Luches is offline
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Join Date: Jul 2009
Posts: 177
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Hi bratattack,

Don't get played by people who want to show off their chemical knowledge, instead of teaching you how to calculate nutrients.

Do yourself a favor and forget about the quoted text and all your examples you have cited, as quickly as possible.

Here is how it actually works in simple terms:
1. Get or take a list of all needed (and appropriate) chemical components to compose nutrients first. No need to know anything about other components or elements that you will not actually need nor use!

2. Inquire the elemental percentage of NPK, Ca, Mg, S, and any other needed trace elements contained in these components only. Actually they are determined by molecular weight, but you don't need to bother as others have done this previously. Get a list...

And here is how it has to be done mathematically:

Example for the elemental content in ppm of potassium phosphate Mono (ppm per 1 gram dissolved in 1 liter of water):

P=SUM (weight in gram*52,2)*0,4364/Liter of water
K=SUM(weight in gram*34,6)*0,83/Liter of water

If this isn't clear yet, again: you have a chemical component called potassium phosphate Mono (or monopatassium phosphate), which is commonly used to manufacture nutrients, it contains Phosphorus and Potassium, OK?

The actual content, as in in how many gram you need per liter to get X ppm is determined by the above formula.

Put these formulas in your spreadsheet and replace "weight in gram" by a corresponding field and one for Liter (as in A1 or B2, - any field of your choice). Put in 1gr of potassium phosphate Mono for 1 liter and you should get:

Phosphorus content of 1 gram potassium phosphate Mono dissolved in one liter of water - P=228 ppm
Potassium content of 1 gram potassium phosphate Mono dissolved in one liter of water - K=287 ppm

These are the basics, from there you can either take any component and use the adequate formula, or you simply get a spread-sheet based nutrient calculator and just fill in the required water and gram.
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