Study About Hainengliang-a New Kind Of Disinfectant Applied In Prawn Culture

Hainengliang is a new kind of disinfectant. In this paper, the effect of Hainengliang on improving the quality of culture waters, eradicating the harmful algae and killing the deleterious pathogens were studied. At the same time, the toxicity of Hainengliang to cultured organisms was researched as well. According to these conclusions, the effectiveness of it in the prawn culture were analyzed and evaluated. The results show that:1. The best using concentration of Hainengliang was about 250 mg/L. And with this concentration, the water quality was improved to a certain extent. The experiment results demonstrated that the concentrations of nitrite, ammonium and nitrate were remarkably decreased after 5~10 min, and the maximum rates were 42%, 76% and 44% respectively; pH and DO were both increased a little in 6 h. It also showed that COD had a major decline; the removal rates could reach 74.6%.2. It had a good eradicative efficiency against float aeruginosa and Microcystis aeruginosa, as the reports, the mortality was above 98% only in 3 h. But the condition to Prorocentrum micans Ehrenberg, Prorocentrum minimum and Heterosigma akashiwo Hada was different; the max mortality was only 85% after 24 h.3. During the study, we found Hainengliang did no harm to the prawn with the concentration of 250 mg/L. It didn't have any influence to adult vannamei and adult japonicus. Whereas to Penaeus vannamei and Penaeus japonicus, it influenced more or less. The half concentrations were 1738 mg/L and 948 mg/L, and the safe concentrations were 520 mg/L and 391 mg/L which were both morer than Hainengliang's using concentations—250 mg/L.4. The effects of it to the total numbers of bacteria, heterotrophic bacteria, Vibri, Microcystis aeruginosa and Vibrio were considerable. It could remove the total bacteria in the culture water at a degree of more than 90.0% after 3 h, and could completely remove the heterotrophic bacteria and Vibri after 6 h. In addition, the eradicative efficiency against Microcystis aeruginosa and Vibrio advanced as the using concentration increasing. The eradicative efficiency was 81% and 70%, when the concentration was 50 mg/L; Following 150 mg/L, the eradicative efficiency increased 91% and 94%, respectively; and while the concentration became 250 mg/L, both the eradicative efficiency was 100%.5. Hainengliang made obvious effectiveness in the prawn culture, however, it's using concentration was higher than the others with the same effect. For example, eradicative efficiency to Heterosigma akashiwo Hada was about 100% with the clay at a level of 5mg/L, but as to Hainengliang, 250 mg/L was needed.