Hi, i have been swallowing some scientific litterature lately to try to understand better nutrient solutions. And multiple documents refered to "Mixture Theory" , i find this really interresting so i will try to explain shortly what i understood, and i hope someone could explain if it can be usefull for a hobbyist.
http://scholar.google.fr/scholar_ur...IeVlScpajH2tP4p3BfEj_n2Bw&nossl=1&oi=scholarr
This document explains the theory and how they use it to experiment several nutrient ratios and synthetise results.
So my understanding :
They consider nutrient solution by :
-the relative cation proportions, [K+ ] + [Ca2+] + [Mg2+]
-the relative anion proportions, [NO3 - ] + [H2PO4 - ] + [SO4 2-]
-the total ionic concentration
-the pH
the unit of mesure is mval/l, called equivalent, its a way to consider valency of ions into mass calculations, roughly it consist of considering how much an ion will react with others particles.
This unit is chosen because pH is directly impacted by the reactivity of ions.
So, considering the amount of cations, and anions, and their reactivity we will be able to design a nutrient solution with control on pH and its equilibrium.
One part i didnt understand is, it seems imortant to keep a equivalent quantity in anions and cations, because if one will be in excess, some of the ions will become unavailable for plants?
The consequence is, if you want to raise an element (K+ for exemple) you have to lower in the same equivalent quantity an other cation (Ca++ or Mg++), so you dont fuck the equilibrium of ions and the pH.
http://scholar.google.fr/scholar_ur...IeVlScpajH2tP4p3BfEj_n2Bw&nossl=1&oi=scholarr
This document explains the theory and how they use it to experiment several nutrient ratios and synthetise results.
So my understanding :
They consider nutrient solution by :
-the relative cation proportions, [K+ ] + [Ca2+] + [Mg2+]
-the relative anion proportions, [NO3 - ] + [H2PO4 - ] + [SO4 2-]
-the total ionic concentration
-the pH
the unit of mesure is mval/l, called equivalent, its a way to consider valency of ions into mass calculations, roughly it consist of considering how much an ion will react with others particles.
This unit is chosen because pH is directly impacted by the reactivity of ions.
So, considering the amount of cations, and anions, and their reactivity we will be able to design a nutrient solution with control on pH and its equilibrium.
One part i didnt understand is, it seems imortant to keep a equivalent quantity in anions and cations, because if one will be in excess, some of the ions will become unavailable for plants?
The consequence is, if you want to raise an element (K+ for exemple) you have to lower in the same equivalent quantity an other cation (Ca++ or Mg++), so you dont fuck the equilibrium of ions and the pH.
