This paper explains the computation of Chloride in sea water using Back propagation Algorithm Neural Network and Genetic Algorithm based Back Propagation Neural Network to identify the best technique that could adequately predict the Chloride concentration. Sea water samples are collected from Middle East coastal region of Tamil Nadu. Temperature, pH and Electrical Conductivity are used as input parameters in the Chloride prediction system. The adaptiveness is checked for various seasonal conditions by varying the input parameters. The performances of the derived methods confirmed that the method derived using Genetic Algorithm based Back propagation Neural Network gave a better prediction.