Seachem flourish potassium contains 50 000 mgl of potassium suitable for the natural planted aquarium potassium is one of several elements that are vitally important to maintaining a vigorous level of growth in a planted aquarium potassium can become depleted in a rapidly growing system or when the source water has a low mineral content in these cases potassium could become the limiting factor to growthr use flourish potassium to prevent potassium depletion signs of which include yellowing