The major components of the TDS were carbonates, sodium, calcium and chloride (Table 1). The groundwater had a pH of 7.9. The mean concentrations of major components, pH, and conductivity of water used in the cultures resulting to the addition of KCl and MgNO
in which shrimp– tomato were cultivated during the first week of culture cycle is presented in Table 1. These additions and the management of the tanks provoked an increase in pH that was probably associated with impurities in the fertilizers and the presence of organic matter and their decomposition product