In order to be soluble, humates in raw form such as lignite or leonardite must go through an alkaline extraction process. Any of the salts like potassium hydroxide, sodium hydroxide or ammonium hydroxide can be used as the extractant. The potassium hydroxide extracted form is preferred for fertilizing application as potassium hydroxide (the extractant) is acceptable to many of the organic registration bodies while sodium hydroxide and ammonium hydroxide are not. Due to the low use rate of soluble humates they are not used as a main source of potassium for crops. The potassium is only there as a result of the extractant used. We do not advise increasing the level of potassium beyond what is already in our product as it will raise the pH and place the product in the “Dangerous Goods” category for transport which is much more costly. If you require potassium for the crop we recommend using normal potassium sulphate applied with a 5% inclusion of Soluble Humate Granules.