The Role of Potassium in Waterbodies Because potassium salts are readily soluble in water, potassium is found primarily in dissolved form in waterbodies rather than in particulate form.

The concentration of potassium in natural surface water is generally less than 10 mg/L, but potassium concentrations as high as 100 mg/L can occur. Potassium is essential to plant and animal nutrition. Because potassium concentrations in freshwaters are generally adequate for meeting the nutritional needs of the biological community, potassium is not usually considered as being a limiting nutrient like phosphorus and nitrogen.

In Florida
Waterbodies in the Florida LAKEWATCH database analyzed prior to January 1998 had potassium levels ranging from 0 to 50 mg/L. Over 75% of these waterbodies had potassium concentrations generally occur naturally along the coast, because marine waters have higher average potassium concentrations than freshwater. If potassium concentrations in a coastal area waterbody are uncharacteristically high, it may indicate saltwater is seeping through the ground into the waterbody in a process called saltwater intrusion.

Health Concerns
Potassium concentrations at the levels found in freshwaters cause no known direct or indirect human health problems.