ReeFlowersAquaPlants Potash�is a highly concentrated potassium solution. It has been specially formulated for aquarium plants and contains a minimum of 40,000 ppm potassium per liter. Potassium is the most important element for plant development and health. It is used in the process of photosynthesis and is very important for the various biochemical reactions that take place in plant tissue. It promotes growth and effects root development. A potassium deficiency causes leaves to wither and tissue to decay from the outside in. Unless the deficiency is remedied, plants may die due to lack of sufficient chlorophyll production. The potassium level should be kept in the range of 20-30 ppm in aquariums with plants.