The Potassium content of natural waters is usually low as it is largely insoluble in water in most forms. Most natural waters contain less than 20 mg/l of potassium, but waters containing several hundred milligrams per litre are occasionally found. Potassium is essential to animal nutrition, but a concentration of 1000 to 2000 mg/l in stock water is regarded as the extreme limit permissible.
Potassium can also be found in water where Potassium Chloride or Potassium/Sodium Chloride is used as a water softener/regenerator. However, people with specific diseases or on certain medications may be susceptible to hyperkalaemia. In these situations, using Potassium Chloride should be avoided and the more traditional Sodium Chloride softeners should be used.