Problem statement: This study is to maintain the interacting liquid level and pH parameter at a desired value. The purpose of decoupling and linearization algorithm is to prevent interaction and making the system linear. Approach: In this study Hirchorn's and Genetic Algorithms (GA) are proposed to make the system linear, non interacting system. This study presents the performance comparison of Hirschorn's (decoupling and linearization algorithm) and Genetic Algorithms (GA) for a approximated model of Interacting level and pH non-linear process. Results: Closed loop simulation was carried out incorporating the above algorithm and the results are compared. Control performance with Hirschorn's is found to give better results than with GA. Conclusion: This study demonstrates the effectiveness of Hirchorn's algorithm in MIMO nonlinear interacting process. Obtained control laws for Hirschorn's algorithm give improved values for Settling Time (Ts) and Integral Square Error (ISE). © 2012 Science Publications.