The present work aimed to use the acidification of water to improve some water quality parameters for rearing the fingerlings of striped catfish, Pangasiandon hypophthalmus. Two hundred of striped catfish juveniles (1.1±0.2 g) were stocked in 1000-L Polypropylene tanks (PP)for twelve weeks. In the control tanks, the water's pH was left unaltered throughout the entire study, allowing it to naturally fluctuate. In the acidification treatment, however, the pH of the culture water was purposely made slightly acidic (between 6.5 and 6.8) by daily addition of concentrated acetic acid (99% conc.). Acidification of water was significantly able to improve some of the water quality parameters as well as the final body weight, specific growth rate, and fish yield.  Based on the findings, it can be inferred that the process of water acidification is a good, applicable, and cheap treatment method for the removal of the toxicity of ammonia in fish farming units with limited water exchange.