Abstract. The study aimed to evaluate the effect of low pH water from acid sulfate soil on growth parameters and digestive enzyme activities of striped catfish (Pangasianodon hypophthalmus) fingerling stage (11.1±0.12 g). The fish was exposed to six levels of water pH including 4.5, 5.0, 5.5, 6.0, 6.5, and 7.2 (tap water as control). The treatments were randomly arranged and triplicated in 500-L fiberglass tanks with a density of 40 fish per tank for 60 days. The results showed that the average fish weights at the pH 6.0, 6.5, and 7.2 (control) treatments were significantly higher than those at the pH 4.5, 5.0, and 5.5 treatment (p < 0.05), and the highest was in the pH 6.5 treatment (40.1±0.22 g). The longest body length was found in the pH 6.5 treatment (17.2±0.12 cm), statistically significant in comparison with fish at the pH 4.5 treatment (14.1±0.47 cm) (p < 0.05). The daily weight gain (DWG) and specific growth rate (SGR) were highest at the pH 6.5 treatment compared to the other treatments. The feed conversion ratio (FCR) was highest at the pH of 6.5 (1.08) while the lowest was at the pH 4.5 (1.64). The survival rates fluctuated between 92.5 and 96.6%, but they were insignificantly different among treatments. The activities of trypsin and chymotrypsin enzymes were significantly decreased in the fish reared in the pH lower than 6.0 while pepsin and amylase enzyme activities showed no effect by the pH levels. The results suggest that the acid sulfate soil areas with slightly low pH (about 6.5) could be considered for striped catfish aquaculture.

(Source: https://www.proquest.com/scholarly-journals/effects-acidic-sulfate-water-on-growth-survival/docview/2652912190/se-2?accountid=28030)