More info on plant fertiliser for growing
What does N-P-K actually mean on my fertiliser?
The letters stand for the chemical elements N = nitrogen, P = phosphorus and K = potassium. The numbers behind them are percentages by weight. E.g. Cultivalley Stardust NPK 0-52-34 means: in 100g fertiliser salt are contained: 0g N, 52g P2O5, 34g K2O5 and 14g ballast salts, which our plants cannot do anything with.
And what are these ballast salts?
If we add the NPK specification of e.g. Cultivalley Growth Fertiliser NPK 20-5-10-(+2Mg), we get 37w.% nutrients. Logically, this means that 63% of the salt is not absorbed by the plant and remains in the nutrient solution. That is why we recommend replacing the nutrient solution after four weeks at the latest to ensure a constant supply of nutrients.
What actually are micronutrients?
Plants consist of more than 90% of the elements hydrogen (H), carbon (C) and oxygen (O). Nature has these elements in abundance in the air and water, which is why we do not consider them nutrients in plant nutrition. When the plants have been dried - we then speak of dry matter - it still consists of 90-95% of the elements H, O and C. This is because sugar and cellulose are made of these elements. This is because sugar and cellulose, the skeleton of plants, are made of these elements.
By burning, we remove these hydrocarbons and then retain 5g of 100g plant mass. Of this, approx. 4.4g are N-P-K-Ca, our main nutrients, and approx. 0.5g Mg and S, the so-called secondary nutrients. The remaining 0.1g is distributed among all the micronutrients. These are: Iron (Fe), manganese (Mn), boron (B), copper (Cu), molybdenum (Mo) and chlorine (Cl). Iron has the highest proportion, as it is needed to build up Chlorophyll.