Use Of Coconut Husk Chips for Potting Medium

[poweramps]

Bad rep of coco husk chips is due to the CEC of the media. It means that you cannot remove the sodium and potassium by just flushing with water alone. Protons (H+) in water cannot dislodge the sodium and potassium from the media even if you use a whole load of water. Unfortunately, when roots of plants come in contact with the media, the sodium can, by ion exchage mechanism, move to the tissue of the plant, burning it. By using cations with a larger atomic number (electronegativity and ionic radius) in the wash water, ie salts in group II or further down the periodic table, the sodium and potassium is dislodged and washed off. The choice of salts is therefore one that is less or non-toxic to plants. Looking at the periodic table, Mg and Ca are good choices (Cu, Cd, Pb and Cr would work wonders, but they are toxic as well, being heavy metals). If coco cubes are treated in this manner, it doesn't matter if they started off high salt or low salt. All you have to do is to do is to prepare a series of ion exchange solutions to remove the sodium.