Many ponds in the southeastern United States have waters with less than 20 mg/ I total alkalinity and should be limed to insure good response to inorganic fertilization. Water analysis is the only technique for determining if a pond needs liming, and the liming rate can best be estimated from a lime requirement determination of the bottom mud. In some waters total alkalinity may be high, but total hardness low. Such waters frequently develop dangerously high pH when fertilized. Alum rather than acid forming fertilizers should be used as emergency treatment to prevent fish kills during periods of high pH. Data on alkalinity and hardness are therefore needed when making fertilizer recommendations for individual ponds. Sufficiently accurate water analyses may be made with water analysis kits, provided reasonable care is exercised.
